[SPARK-9327] [DOCS] Fix documentation about classpath config options.
[SPARK-9327] [DOCS] Fix documentation about classpath config options.

Author: Marcelo Vanzin <vanzin@cloudera.com>

Closes #7651 from vanzin/SPARK-9327 and squashes the following commits:

2923e23 [Marcelo Vanzin] [SPARK-9327] [docs] Fix documentation about classpath config options.

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