Remove mention of lpreview from BUILDING.md
Remove mention of lpreview from BUILDING.md

Removed lpreview build section
Updated gradle commands (removed lpreview and classic productFlavors)
Updated SDK Manager packages needed (removed kiktkat, included lollipop)

SDK Build-tools version 21 has solved and unsolved issues, Current rev is 21.0.1
https://code.google.com/p/android/issues/detail?id=77629
http://stackoverflow.com/questions/26446610/android-gradle-project-upgrading-build-tools-to-21-0-1-aapt-throws-exception
ZJsnowman/iosched,zhou531078929/googleDemoiosched,aecca/iosched,hejunbinlan/iosched,mumer92/iosched,lcyluo/iosched,nikolaz5/iosched,ashcoding/iosched,omkarnanda/Android-UI-demos,astroboyapple/iosched,abhishek011/Test,liviubirau/iosched,ztingle/GoogleIO-APP,chenanze/iosched,kyotoalgo/iosched,omkarnanda/Android-UI-demos,angeliaz/iosched,jarekankowski/iosched,ZJsnowman/iosched,DCSH2O/iosched,PareshMayani/iosched,divyatman/iosched,aecca/iosched,Dreezydraig/iosched,HeZaiJin/iosched,kmdupr33/iosched,PriyaSGit/iosched,ipalermo/schedo,fabiel016/iosched,GeorgeMe/iosched,HeZaiJin/iosched,yuzhiboi/iosched,13yo/iosched,MonoCloud/iosched,samirshrestha/iosched,zayenCh/iosched,ipmobiletech/iosched,yarhtut/iosched,Chuck8080/iosched,astroboyapple/iosched,divyatman/iosched,tanweijiu/iosched,nguyenducnhaty/iosched,GeorgeMe/iosched,Dvik/iosched,hejunbinlan/iosched,ma5069073/iosched,xuanduc939/iosched,GeorgeMe/iosched,jairofloress/iosched,ztingle/GoogleIO-APP,google/iosched,jianxiansining/iosched,VictorJava/iosched,zeetherocker/iosched,fabiel016/iosched,PranaySPatil/iosched,PriyaSGit/iosched,mumer92/iosched,Logan676/iosched,TribeMedia/iosched,hejunbinlan/iosched,lichen79/iosched,PranaySPatil/iosched,TedaLIEz/iosched,408873559/Stealer,TonyTangAndroid/iosched,liuqiwang01/iosched,yzpniceboy/iosched,TwentySevenC/iosched,griddynamics/iosched-ibeacon-for-joker,silicon-mountain/smconf-android,chantw172/iosched,erpragatisingh/iosched,BanNT/iosched,sachin-appdev/iosched,ztingle/GoogleIO-APP,andrewpetrovic/iosched,chantw172/iosched,Lareth51/iosched,noxiouswinter/iosched-copy,ipalermo/schedo,kingslou/iosched,lichen79/iosched,yarhtut/iosched,eliezerint/iosched,tanweijiu/iosched,jjdstr/iosched,b-cuts/iosched,sophiataskova/iosched,NileshJarad/iosched,vovs/confs2015,ardock/iosched,cliffmoturi/iosched,TribeMedia/iosched,tjit777-naver-com/iosched,sebas-tc/iosched,poovarasanvasudevan/iosched,romannurik/iosched,Dvik/iosched,Arisono/iosched,silent-nischal/iosched,Patrichuan/iosched,408873559/Stealer,andersonb/iosched,wangziqiang/iosched,umitems/iosched,BanNT/iosched,AdrianHsu/iosched,eeVoskos/iosched,chrooter/iosched,astroboyapple/iosched,abhishek011/Test,ash663/iosched,PaulRashidi/iosched,TribeMedia/iosched,silent-nischal/iosched,tnaffh/iosched,sbo3000/iosched,griddynamics/iosched-ibeacon-for-joker,Logan676/iosched,AdrianHsu/iosched,sachin-appdev/iosched,cliffmoturi/iosched,tnaffh/iosched,b-cuts/iosched,TonyTangAndroid/iosched,poovarasanvasudevan/iosched,vovs/confs2015,Logan676/iosched,zeetherocker/iosched,ma5069073/iosched,ardock/iosched,ben-upsilon/iosched,b-cuts/iosched,ashcoding/iosched,xiaoyanit/iosched-1,gaikwad411/iosched,zuoyanyouwu/iosched,deshion/iosched,yoube/iosched,haichuand/iosched,lokling/AndroiditoJZ,madisp/iosched,rock3r/iosched-2014,haichuand/iosched,janzoner/iosched,10045125/iosched,eliezerint/iosched,dxiaogang/iosched,hxddh/iosched,samirshrestha/iosched,MonoCloud/iosched,zeetherocker/iosched,fsolovyev/iosched-ibeacon-for-joker,The-WebOps-Club/saarang-iosched,nguyenhoanglam/iosched,sudanamin/iosched,vivekchand/iosched,romannurik/iosched,Lareth51/iosched,AndroidBase/iosched,eliezerint/iosched,ipalermo/schedo,chenanze/iosched,legua25/iosched-2014,dARKf3n1Xx/iosched,liuqiwang01/iosched,Pradeet/iosched,aelx311/iosched,chrooter/iosched,lokeshpancharia/iosched,ashcoding/iosched,theDL/iosched,witchlock/iosched,lokling/AndroiditoJZ,heymind/iosched,witchlock/iosched,andersonb/iosched,cliffmoturi/iosched,rayzone107/iosched,aecca/iosched,PibeDx/iosched,tnaffh/iosched,408873559/Stealer,jairofloress/iosched,ipmobiletech/iosched,PriyaSGit/iosched,trigged/iosched,vivekchand/iosched,ardock/iosched,heymind/iosched,DCSH2O/iosched,hubaoyu/iosched,Brooks0129/iosched,lokeshpancharia/iosched,yzpniceboy/iosched,lichen79/iosched,Huihuiyule-www/iosched,yzpniceboy/iosched,huangxueqiang/iosched,rayzone107/iosched,andrewpetrovic/iosched,zayenCh/iosched,sbo3000/iosched,xuanduc939/iosched,ronzohan/iosched,janzoner/iosched,chenanze/iosched,spicykaiju/iosched,kyotoalgo/iosched,10045125/iosched,aelx311/iosched,theDL/iosched,trigged/iosched,hxddh/iosched,lokling/AndroiditoJZ,Prographer/iosched,heymind/iosched,xiaoyanit/iosched-1,gh0stbird/iosched,TonyTangAndroid/iosched,rhlass/iosched,kingslou/iosched,ronzohan/iosched,WeRockStar/iosched,PibeDx/iosched,epiphany27/iosched,madisp/iosched,charany1/iosched,muchbeer/iosched,amardeshbd/iosched,liviubirau/iosched,gaikwad411/iosched,soulduse/iosched,Chuck8080/iosched,NileshJarad/iosched,DCSH2O/iosched,samirshrestha/iosched,bhargav175/iosched,tanweijiu/iosched,deshion/iosched,jotajr/iosched,Brooks0129/iosched,madisp/iosched,nguyenhoanglam/iosched,ash663/iosched,Logan676/iosched,tjit777-naver-com/iosched,lokeshpancharia/iosched,Arisono/iosched,yoube/iosched,PareshMayani/iosched,yuzhiboi/iosched,zhangfy068/iosched,opozo/android-material-io,poovarasanvasudevan/iosched,legua25/iosched-2014,PibeDx/iosched,nikolaz5/iosched,zeXtreme/iosched,zhangfy068/iosched,erpragatisingh/iosched,silicon-mountain/smconf-android,The-WebOps-Club/saarang-iosched,zeXtreme/iosched,hggliu/iosched,jianxiansining/iosched,VictorJava/iosched,eeVoskos/iosched,jotajr/iosched,yummy222/iosched,wangziqiang/iosched,tjit777-naver-com/iosched,BanNT/iosched,virm0nd/iosched,The-WebOps-Club/saarang-iosched,nguyenhoanglam/iosched,skaushikgit/iosched,TwentySevenC/iosched,TouchBoarder/iosched,ben-upsilon/iosched,Brooks0129/iosched,ipmobiletech/iosched,zhou531078929/googleDemoiosched,ryantaoyf/iosched,virm0nd/iosched,yuzhiboi/iosched,yummy222/iosched,epiphany27/iosched,yoube/iosched,NileshJarad/iosched,TedaLIEz/iosched,douglasjunior/iosched,jotajr/iosched,TribeMedia/iosched,gaikwad411/iosched,google/iosched,skaushikgit/iosched,yummy222/iosched,umitems/iosched,ajsky/iosched,wing2407/iosched,spicykaiju/iosched,skaushikgit/iosched,chrooter/iosched,legua25/iosched-2014,bhargav175/iosched,WeRockStar/iosched,andysinlight/iosched,PranaySPatil/iosched,fsolovyev/iosched-ibeacon-for-joker,jjdstr/iosched,PaulRashidi/iosched,AdrianHsu/iosched,kmdupr33/iosched,TweetMap/iosched,ardock/iosched,vivekchand/iosched,hubaoyu/iosched,fabiel016/iosched,sebas-tc/iosched,angeliaz/iosched,madisp/iosched,ben-upsilon/iosched,TouchBoarder/iosched,PareshMayani/iosched,andysinlight/iosched,Dvik/iosched,wing2407/iosched,spicykaiju/iosched,ScHaFeR/iosched,nikolaz5/iosched,sudanamin/iosched,douglasjunior/iosched,VictorJava/iosched,wangziqiang/iosched,amardeshbd/iosched,opozo/android-material-io,kyotoalgo/iosched,TouchBoarder/iosched,hubaoyu/iosched,yarhtut/iosched,dARKf3n1Xx/iosched,ScHaFeR/iosched,eeVoskos/iosched,divyatman/iosched,bhargav175/iosched,muchbeer/iosched,dARKf3n1Xx/iosched,griddynamics/iosched-ibeacon-for-joker,liuqiwang01/iosched,jarekankowski/iosched,zhangfy068/iosched,sbo3000/iosched,sophiataskova/iosched,zayenCh/iosched,xiaoyanit/iosched-1,soulduse/iosched,charany1/iosched,erpragatisingh/iosched,google/iosched,ash663/iosched,xiaoyanit/iosched-1,jairofloress/iosched,rayzone107/iosched,ScHaFeR/iosched,nguyenducnhaty/iosched,TouchBoarder/iosched,sachin-appdev/iosched,Prographer/iosched,Arisono/iosched,Dreezydraig/iosched,lcyluo/iosched,ZJsnowman/iosched,ajsky/iosched,opozo/android-material-io,janzoner/iosched,trigged/iosched,liviubirau/iosched,theDL/iosched,wing2407/iosched,Pradeet/iosched,zuoyanyouwu/iosched,dxiaogang/iosched,silicon-mountain/smconf-android,samirshrestha/iosched,Patrichuan/iosched,andrewpetrovic/iosched,vilyever/iosched,TweetMap/iosched,rhlass/iosched,Patrichuan/iosched,zeXtreme/iosched,hxddh/iosched,dxiaogang/iosched,xuanduc939/iosched,TedaLIEz/iosched,huangxueqiang/iosched,nguyenducnhaty/iosched,kmdupr33/iosched,Prographer/iosched,jianxiansining/iosched,gh0stbird/iosched,janzoner/iosched,zuoyanyouwu/iosched,zhou531078929/googleDemoiosched,virm0nd/iosched,sophiataskova/iosched,sudanamin/iosched,muchbeer/iosched,omkarnanda/Android-UI-demos,vilyever/iosched,vilyever/iosched,rhlass/iosched,soulduse/iosched,silent-nischal/iosched,kingslou/iosched,huangxueqiang/iosched,sebas-tc/iosched,WeRockStar/iosched,silicon-mountain/smconf-android,ronzohan/iosched,TwentySevenC/iosched,witchlock/iosched,gh0stbird/iosched,ben-upsilon/iosched,ajsky/iosched,ashcoding/iosched,AndroidBase/iosched,HeZaiJin/iosched,lichen79/iosched,umitems/iosched,epiphany27/iosched,Huihuiyule-www/iosched,haichuand/iosched,jarekankowski/iosched,deshion/iosched,charany1/iosched,ryantaoyf/iosched,Lareth51/iosched,mumer92/iosched,hggliu/iosched,andersonb/iosched,ryantaoyf/iosched,chantw172/iosched,zuoyanyouwu/iosched,aelx311/iosched,PareshMayani/iosched,noxiouswinter/iosched-copy,douglasjunior/iosched,zhou531078929/googleDemoiosched,TweetMap/iosched,13yo/iosched,Huihuiyule-www/iosched,andysinlight/iosched,vovs/confs2015,Pradeet/iosched,rock3r/iosched-2014,ma5069073/iosched,hggliu/iosched,ztingle/GoogleIO-APP,lcyluo/iosched,fsolovyev/iosched-ibeacon-for-joker,Dreezydraig/iosched,amardeshbd/iosched,amardeshbd/iosched,MonoCloud/iosched