Added LZ4 to compression codec in configuration page.
Added LZ4 to compression codec in configuration page.

Author: Reynold Xin <rxin@apache.org>

Closes #1417 from rxin/lz4 and squashes the following commits:

472f6a1 [Reynold Xin] Set the proper default.
9cf0b2f [Reynold Xin] Added LZ4 to compression codec in configuration page.

BryanCutler/spark,ioana-delaney/spark,alunarbeach/spark,haowu80s/spark,MLnick/spark,bdrillard/spark,haowu80s/spark,rezasafi/spark,MLnick/spark,janewangfb/spark,joseph-torres/spark,shuangshuangwang/spark,hvanhovell/spark,ConeyLiu/spark,HyukjinKwon/spark,hvanhovell/spark,cloud-fan/spark,xflin/spark,pgandhi999/spark,UndeadBaneGitHub/spark,metamx/spark,ddna1021/spark,ptkool/spark,mahak/spark,rekhajoshm/spark,ahnqirage/spark,someorz/spark,cloud-fan/spark,witgo/spark,setjet/spark,nchammas/spark,alunarbeach/spark,gengliangwang/spark,kimoonkim/spark,tejasapatil/spark,saltstar/spark,szhem/spark,jlopezmalla/spark,kiszk/spark,1haodian/spark,ueshin/apache-spark,saturday-shi/spark,rekhajoshm/spark,huang1900/spark,bOOm-X/spark,zhouyejoe/spark,kevinyu98/spark,panfengfeng/spark,kissmetrics/spark,gengliangwang/spark,sureshthalamati/spark,aosagie/spark,Panos-Bletsos/spark-cost-model-optimizer,guoxiaolongzte/spark,zhouyejoe/spark,nlalevee/spark,bravo-zhang/spark,stanzhai/spark,witgo/spark,mahak/spark,maropu/spark,rezasafi/spark,jiangxb1987/spark,saltstar/spark,srowen/spark,icexelloss/spark,witgo/spark,techaddict/spark,guoxiaolongzte/spark,sureshthalamati/spark,huang1900/spark,kimoonkim/spark,zero323/spark,big-pegasus/spark,andrewor14/iolap,huang1900/spark,hhbyyh/spark,metamx/spark,akopich/spark,jrshust/spark,pronix/spark,rikima/spark,bdrillard/spark,ron8hu/spark,dongjoon-hyun/spark,taroplus/spark,poffuomo/spark,dhruve/spark,shaneknapp/spark,WindCanDie/spark,nchammas/spark,publicRoman/spark,zero323/spark,saltstar/spark,bOOm-X/spark,zero323/spark,jkbradley/spark,huang1900/spark,jlopezmalla/spark,jiangxb1987/spark,narahari92/spark,brad-kaiser/spark,akopich/spark,xuanyuanking/spark,zzcclp/spark,BryanCutler/spark,1haodian/spark,tengpeng/spark,mzl9039/spark,esi-mineset/spark,Aegeaner/spark,sureshthalamati/spark,maropu/spark,bravo-zhang/spark,alunarbeach/spark,chuckchen/spark,debugger87/spark,rezasafi/spark,UndeadBaneGitHub/spark,BryanCutler/spark,nilsgrabbert/spark,narahari92/spark,liutang123/spark,MLnick/spark,brad-kaiser/spark,publicRoman/spark,SnappyDataInc/spark,xflin/spark,ptkool/spark,dhruve/spark,lvdongr/spark,aokolnychyi/spark,janewangfb/spark,jkbradley/spark,aokolnychyi/spark,icexelloss/spark,publicRoman/spark,nlalevee/spark,shaneknapp/spark,skonto/spark,actuaryzhang/spark,liyichao/spark,aray/spark,ron8hu/spark,publicRoman/spark,JoshRosen/spark,cloud-fan/spark,HyukjinKwon/spark,ddna1021/spark,ron8hu/spark,SHASHANKB/spark,wangyum/spark,gioenn/xSpark,ioana-delaney/spark,kissmetrics/spark,kevinyu98/spark,srowen/spark,kiszk/spark,Panos-Bletsos/spark-cost-model-optimizer,saturday-shi/spark,haowu80s/spark,tengpeng/spark,srowen/spark,mdespriee/spark,jiangxb1987/spark,yanboliang/spark,cloud-fan/spark,janewangfb/spark,brad-kaiser/spark,rikima/spark,WindCanDie/spark,szhem/spark,xflin/spark,ahnqirage/spark,ConeyLiu/spark,jkbradley/spark,goldmedal/spark,chuckchen/spark,techaddict/spark,janewangfb/spark,Aegeaner/spark,zhouyejoe/spark,saltstar/spark,facaiy/spark,michalsenkyr/spark,JerryLead/spark,wangyum/spark,ahnqirage/spark,zhouyejoe/spark,yanboliang/spark,loneknightpy/spark,saturday-shi/spark,shaneknapp/spark,WeichenXu123/spark,skonto/spark,setjet/spark,icexelloss/spark,jianran/spark,gengliangwang/spark,someorz/spark,wangmiao1981/spark,1haodian/spark,byakuinss/spark,ioana-delaney/spark,jrshust/spark,alunarbeach/spark,mike0sv/spark,SHASHANKB/spark,eyalfa/spark,xuanyuanking/spark,Panos-Bletsos/spark-cost-model-optimizer,mdespriee/spark,aosagie/spark,nchammas/spark,narahari92/spark,ajaysaini725/spark,dhruve/spark,rednaxelafx/apache-spark,holdenk/spark,joseph-torres/spark,highfei2011/spark,highfei2011/spark,wangyum/spark,rezasafi/spark,patrick-nicholson/spark,highfei2011/spark,srowen/spark,rekhajoshm/spark,loneknightpy/spark,dhruve/spark,kimoonkim/spark,dhruve/spark,ibm-research-ireland/sparkoscope,rekhajoshm/spark,byakuinss/spark,rikima/spark,tengpeng/spark,bOOm-X/spark,dongjoon-hyun/spark,markhamstra/spark,taroplus/spark,WindCanDie/spark,actuaryzhang/spark,dbtsai/spark,kiszk/spark,eyalfa/spark,esi-mineset/spark,SHASHANKB/spark,publicRoman/spark,hhbyyh/spark,shaneknapp/spark,taroplus/spark,Aegeaner/spark,Aegeaner/spark,zuotingbing/spark,pgandhi999/spark,someorz/spark,loneknightpy/spark,facaiy/spark,sachintyagi22/spark,ajaysaini725/spark,rednaxelafx/apache-spark,kissmetrics/spark,yanboliang/spark,apache-spark-on-k8s/spark,patrick-nicholson/spark,kimoonkim/spark,darionyaphet/spark,shuangshuangwang/spark,LantaoJin/spark,ericvandenbergfb/spark,byakuinss/spark,rikima/spark,ericvandenbergfb/spark,stanzhai/spark,spark-test/spark,rednaxelafx/apache-spark,markhamstra/spark,zero323/spark,mzl9039/spark,yanboliang/spark,cin/spark,aokolnychyi/spark,liyichao/spark,ron8hu/spark,publicRoman/spark,joseph-torres/spark,UndeadBaneGitHub/spark,BryanCutler/spark,rednaxelafx/apache-spark,icexelloss/spark,guoxiaolongzte/spark,holdenk/spark,metamx/spark,panfengfeng/spark,holdenk/spark,szhem/spark,witgo/spark,byakuinss/spark,HyukjinKwon/spark,HyukjinKwon/spark,debugger87/spark,caneGuy/spark,aray/spark,aray/spark,liutang123/spark,mahak/spark,actuaryzhang/spark,gioenn/xSpark,kevinyu98/spark,narahari92/spark,saltstar/spark,andrewor14/iolap,sureshthalamati/spark,milliman/spark,JoshRosen/spark,goldmedal/spark,szhem/spark,Panos-Bletsos/spark-cost-model-optimizer,andrewor14/spark,lvdongr/spark,jlopezmalla/spark,WeichenXu123/spark,mdespriee/spark,sachintyagi22/spark,skonto/spark,tejasapatil/spark,nilsgrabbert/spark,loneknightpy/spark,vinodkc/spark,darionyaphet/spark,akopich/spark,WeichenXu123/spark,gengliangwang/spark,milliman/spark,rikima/spark,zzcclp/spark,jiangxb1987/spark,rednaxelafx/apache-spark,hvanhovell/spark,techaddict/spark,joseph-torres/spark,apache-spark-on-k8s/spark,szhem/spark,ddna1021/spark,pronix/spark,debugger87/spark,taroplus/spark,highfei2011/spark,mzl9039/spark,andrewor14/spark,map222/spark,gengliangwang/spark,cin/spark,esi-mineset/spark,goldmedal/spark,setjet/spark,aosagie/spark,ibm-research-ireland/sparkoscope,tejasapatil/spark,rekhajoshm/spark,liyichao/spark,adrian-ionescu/apache-spark,techaddict/spark,icexelloss/spark,bravo-zhang/spark,alunarbeach/spark,xuanyuanking/spark,vinodkc/spark,chuckchen/spark,mike0sv/spark,pronix/spark,mahak/spark,ioana-delaney/spark,michalsenkyr/spark,nchammas/spark,dbtsai/spark,szhem/spark,eyalfa/spark,tengpeng/spark,wzhfy/spark,zero323/spark,LantaoJin/spark,mike0sv/spark,michalsenkyr/spark,spark-test/spark,hvanhovell/spark,panfengfeng/spark,pronix/spark,sureshthalamati/spark,liutang123/spark,JerryLead/spark,jrshust/spark,poffuomo/spark,vinodkc/spark,jiangxb1987/spark,ibm-research-ireland/sparkoscope,hvanhovell/spark,big-pegasus/spark,WindCanDie/spark,pronix/spark,minixalpha/spark,lxsmnv/spark,apache/spark,xflin/spark,zero323/spark,actuaryzhang/spark,bOOm-X/spark,zzcclp/spark,tengpeng/spark,apache-spark-on-k8s/spark,zuotingbing/spark,maropu/spark,jiangxb1987/spark,dbtsai/spark,michalsenkyr/spark,metamx/spark,ioana-delaney/spark,mahak/spark,caneGuy/spark,saturday-shi/spark,aosagie/spark,zuotingbing/spark,tengpeng/spark,SnappyDataInc/spark,shuangshuangwang/spark,wangyum/spark,saltstar/spark,bravo-zhang/spark,LantaoJin/spark,sahilTakiar/spark,WindCanDie/spark,apache/spark,WindCanDie/spark,zzcclp/spark,dhruve/spark,janewangfb/spark,maropu/spark,andrewor14/spark,dongjoon-hyun/spark,lxsmnv/spark,bdrillard/spark,sahilTakiar/spark,debugger87/spark,mike0sv/spark,esi-mineset/spark,rezasafi/spark,andrewor14/iolap,patrick-nicholson/spark,jkbradley/spark,JerryLead/spark,Aegeaner/spark,panfengfeng/spark,kimoonkim/spark,SnappyDataInc/spark,adrian-ionescu/apache-spark,HyukjinKwon/spark,saturday-shi/spark,jrshust/spark,map222/spark,SHASHANKB/spark,wzhfy/spark,wangmiao1981/spark,map222/spark,stanzhai/spark,pgandhi999/spark,andrewor14/iolap,WeichenXu123/spark,markhamstra/spark,aray/spark,aosagie/spark,eyalfa/spark,sachintyagi22/spark,facaiy/spark,eyalfa/spark,shubhamchopra/spark,pgandhi999/spark,huang1900/spark,byakuinss/spark,1haodian/spark,pronix/spark,ueshin/apache-spark,JerryLead/spark,sahilTakiar/spark,big-pegasus/spark,akopich/spark,kissmetrics/spark,WindCanDie/spark,rezasafi/spark,brad-kaiser/spark,zzcclp/spark,mahak/spark,shuangshuangwang/spark,wangmiao1981/spark,darionyaphet/spark,BryanCutler/spark,milliman/spark,minixalpha/spark,ptkool/spark,spark-test/spark,holdenk/spark,ConeyLiu/spark,shuangshuangwang/spark,facaiy/spark,spark-test/spark,joseph-torres/spark,MLnick/spark,facaiy/spark,panfengfeng/spark,wzhfy/spark,wangyum/spark,stanzhai/spark,huang1900/spark,debugger87/spark,dbtsai/spark,SnappyDataInc/spark,shaneknapp/spark,chuckchen/spark,jrshust/spark,map222/spark,goldmedal/spark,darionyaphet/spark,andrewor14/spark,bOOm-X/spark,kiszk/spark,pgandhi999/spark,metamx/spark,JoshRosen/spark,ConeyLiu/spark,stanzhai/spark,kissmetrics/spark,goldmedal/spark,hhbyyh/spark,narahari92/spark,someorz/spark,ericvandenbergfb/spark,gioenn/xSpark,szhem/spark,facaiy/spark,brad-kaiser/spark,witgo/spark,metamx/spark,nlalevee/spark,big-pegasus/spark,gioenn/xSpark,pgandhi999/spark,hhbyyh/spark,nchammas/spark,apache/spark,shuangshuangwang/spark,bravo-zhang/spark,zhouyejoe/spark,shubhamchopra/spark,xuanyuanking/spark,aosagie/spark,zzcclp/spark,wzhfy/spark,milliman/spark,ahnqirage/spark,facaiy/spark,nlalevee/spark,hhbyyh/spark,yanboliang/spark,taroplus/spark,adrian-ionescu/apache-spark,esi-mineset/spark,mzl9039/spark,gengliangwang/spark,aosagie/spark,vinodkc/spark,poffuomo/spark,Panos-Bletsos/spark-cost-model-optimizer,michalsenkyr/spark,cin/spark,jianran/spark,cloud-fan/spark,HyukjinKwon/spark,patrick-nicholson/spark,apache-spark-on-k8s/spark,akopich/spark,cin/spark,apache-spark-on-k8s/spark,setjet/spark,ddna1021/spark,gioenn/xSpark,apache/spark,andrewor14/iolap,debugger87/spark,apache/spark,apache-spark-on-k8s/spark,SnappyDataInc/spark,ddna1021/spark,1haodian/spark,nlalevee/spark,spark-test/spark,HyukjinKwon/spark,mzl9039/spark,UndeadBaneGitHub/spark,spark-test/spark,mahak/spark,jkbradley/spark,xflin/spark,ron8hu/spark,caneGuy/spark,liyichao/spark,yanboliang/spark,shaneknapp/spark,bdrillard/spark,minixalpha/spark,metamx/spark,JerryLead/spark,xflin/spark,liutang123/spark,lvdongr/spark,srowen/spark,liutang123/spark,aray/spark,markhamstra/spark,ibm-research-ireland/sparkoscope,panfengfeng/spark,xflin/spark,spark-test/spark,WeichenXu123/spark,sureshthalamati/spark,loneknightpy/spark,maropu/spark,wzhfy/spark,techaddict/spark,michalsenkyr/spark,lvdongr/spark,ericvandenbergfb/spark,nlalevee/spark,narahari92/spark,taroplus/spark,UndeadBaneGitHub/spark,ron8hu/spark,BryanCutler/spark,skonto/spark,guoxiaolongzte/spark,1haodian/spark,UndeadBaneGitHub/spark,icexelloss/spark,map222/spark,someorz/spark,milliman/spark,hvanhovell/spark,janewangfb/spark,cin/spark,skonto/spark,rezasafi/spark,bOOm-X/spark,rednaxelafx/apache-spark,JoshRosen/spark,panfengfeng/spark,xuanyuanking/spark,ericvandenbergfb/spark,holdenk/spark,mzl9039/spark,ahnqirage/spark,BryanCutler/spark,guoxiaolongzte/spark,ptkool/spark,dbtsai/spark,aokolnychyi/spark,dbtsai/spark,mdespriee/spark,wangyum/spark,ueshin/apache-spark,kimoonkim/spark,apache/spark,haowu80s/spark,ericvandenbergfb/spark,saltstar/spark,mzl9039/spark,alunarbeach/spark,ConeyLiu/spark,poffuomo/spark,esi-mineset/spark,LantaoJin/spark,ueshin/apache-spark,LantaoJin/spark,gioenn/xSpark,milliman/spark,ajaysaini725/spark,lxsmnv/spark,nilsgrabbert/spark,kevinyu98/spark,milliman/spark,janewangfb/spark,narahari92/spark,dhruve/spark,bdrillard/spark,someorz/spark,lxsmnv/spark,guoxiaolongzte/spark,hhbyyh/spark,mdespriee/spark,jrshust/spark,big-pegasus/spark,wangmiao1981/spark,liyichao/spark,goldmedal/spark,markhamstra/spark,bOOm-X/spark,actuaryzhang/spark,gioenn/xSpark,michalsenkyr/spark,jrshust/spark,kissmetrics/spark,mike0sv/spark,tejasapatil/spark,ron8hu/spark,nchammas/spark,andrewor14/iolap,nilsgrabbert/spark,mdespriee/spark,wangmiao1981/spark,JoshRosen/spark,rekhajoshm/spark,MLnick/spark,joseph-torres/spark,andrewor14/iolap,jlopezmalla/spark,jianran/spark,saturday-shi/spark,liyichao/spark,darionyaphet/spark,ddna1021/spark,kissmetrics/spark,mike0sv/spark,zero323/spark,setjet/spark,xuanyuanking/spark,shuangshuangwang/spark,setjet/spark,aokolnychyi/spark,actuaryzhang/spark,ueshin/apache-spark,SnappyDataInc/spark,vinodkc/spark,map222/spark,MLnick/spark,highfei2011/spark,1haodian/spark,pgandhi999/spark,holdenk/spark,kimoonkim/spark,zhouyejoe/spark,wzhfy/spark,setjet/spark,lvdongr/spark,SnappyDataInc/spark,ptkool/spark,haowu80s/spark,sahilTakiar/spark,holdenk/spark,akopich/spark,lxsmnv/spark,rednaxelafx/apache-spark,highfei2011/spark,loneknightpy/spark,caneGuy/spark,dbtsai/spark,SHASHANKB/spark,alunarbeach/spark,ptkool/spark,aray/spark,kiszk/spark,bravo-zhang/spark,cloud-fan/spark,esi-mineset/spark,srowen/spark,ahnqirage/spark,jlopezmalla/spark,poffuomo/spark,skonto/spark,wzhfy/spark,mike0sv/spark,adrian-ionescu/apache-spark,chuckchen/spark,witgo/spark,guoxiaolongzte/spark,SHASHANKB/spark,andrewor14/spark,zuotingbing/spark,rikima/spark,minixalpha/spark,shubhamchopra/spark,lvdongr/spark,UndeadBaneGitHub/spark,brad-kaiser/spark,nilsgrabbert/spark,nilsgrabbert/spark,zuotingbing/spark,vinodkc/spark,lxsmnv/spark,patrick-nicholson/spark,maropu/spark,LantaoJin/spark,zuotingbing/spark,skonto/spark,tengpeng/spark,srowen/spark,joseph-torres/spark,kiszk/spark,WeichenXu123/spark,sachintyagi22/spark,byakuinss/spark,rikima/spark,liutang123/spark,minixalpha/spark,shaneknapp/spark,witgo/spark,tejasapatil/spark,liyichao/spark,techaddict/spark,jianran/spark,chuckchen/spark,jianran/spark,brad-kaiser/spark,bdrillard/spark,ajaysaini725/spark,ajaysaini725/spark,bdrillard/spark,zuotingbing/spark,poffuomo/spark,shubhamchopra/spark,cin/spark,jlopezmalla/spark,andrewor14/spark,dongjoon-hyun/spark,shubhamchopra/spark,ajaysaini725/spark,caneGuy/spark,poffuomo/spark,ConeyLiu/spark,stanzhai/spark,ueshin/apache-spark,Aegeaner/spark,wangyum/spark,dongjoon-hyun/spark,ptkool/spark,jianran/spark,saturday-shi/spark,highfei2011/spark,WeichenXu123/spark,zhouyejoe/spark,hvanhovell/spark,jianran/spark,jkbradley/spark,ibm-research-ireland/sparkoscope,stanzhai/spark,apache/spark,markhamstra/spark,wangmiao1981/spark,markhamstra/spark,ericvandenbergfb/spark,caneGuy/spark,cin/spark,techaddict/spark,tejasapatil/spark,mdespriee/spark,nchammas/spark,Aegeaner/spark,darionyaphet/spark,JerryLead/spark,aokolnychyi/spark,ibm-research-ireland/sparkoscope,sachintyagi22/spark,icexelloss/spark,publicRoman/spark,lvdongr/spark,sachintyagi22/spark,rekhajoshm/spark,akopich/spark,tejasapatil/spark,someorz/spark,nilsgrabbert/spark,nlalevee/spark,andrewor14/spark,zzcclp/spark,kevinyu98/spark,ueshin/apache-spark,aokolnychyi/spark,ddna1021/spark,matthewfranglen/spark,kevinyu98/spark,Panos-Bletsos/spark-cost-model-optimizer,kevinyu98/spark,yanboliang/spark,shubhamchopra/spark,minixalpha/spark,SHASHANKB/spark,JoshRosen/spark,adrian-ionescu/apache-spark,sureshthalamati/spark,eyalfa/spark,caneGuy/spark,jkbradley/spark,huang1900/spark,JoshRosen/spark,apache-spark-on-k8s/spark,ConeyLiu/spark,liutang123/spark,kiszk/spark,bravo-zhang/spark,taroplus/spark,patrick-nicholson/spark,adrian-ionescu/apache-spark,dongjoon-hyun/spark,shubhamchopra/spark,LantaoJin/spark,map222/spark,sahilTakiar/spark,ioana-delaney/spark,ahnqirage/spark,debugger87/spark,darionyaphet/spark,big-pegasus/spark,loneknightpy/spark,actuaryzhang/spark,eyalfa/spark,hhbyyh/spark,chuckchen/spark,patrick-nicholson/spark,minixalpha/spark,ibm-research-ireland/sparkoscope,jiangxb1987/spark,jlopezmalla/spark,MLnick/spark,big-pegasus/spark,ajaysaini725/spark,Panos-Bletsos/spark-cost-model-optimizer,ioana-delaney/spark,haowu80s/spark,wangmiao1981/spark,aray/spark,cloud-fan/spark,lxsmnv/spark,sahilTakiar/spark,maropu/spark,sahilTakiar/spark,dongjoon-hyun/spark,vinodkc/spark,sachintyagi22/spark,gengliangwang/spark,adrian-ionescu/apache-spark,byakuinss/spark,JerryLead/spark,xuanyuanking/spark,goldmedal/spark