Update GRANT example and discussion to match current sources.
Update GRANT example and discussion to match current sources.

lisakowen/gpdb,edespino/gpdb,edespino/gpdb,rvs/gpdb,pavanvd/postgres-xl,zaksoup/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,lpetrov-pivotal/gpdb,ahachete/gpdb,randomtask1155/gpdb,Quikling/gpdb,yazun/postgres-xl,xuegang/gpdb,jmcatamney/gpdb,rvs/gpdb,ahachete/gpdb,cjcjameson/gpdb,yuanzhao/gpdb,kaknikhil/gpdb,foyzur/gpdb,0x0FFF/gpdb,lintzc/gpdb,cjcjameson/gpdb,janebeckman/gpdb,CraigHarris/gpdb,Chibin/gpdb,Chibin/gpdb,edespino/gpdb,randomtask1155/gpdb,chrishajas/gpdb,edespino/gpdb,foyzur/gpdb,tangp3/gpdb,kmjungersen/PostgresXL,pavanvd/postgres-xl,atris/gpdb,foyzur/gpdb,tpostgres-projects/tPostgres,edespino/gpdb,yuanzhao/gpdb,chrishajas/gpdb,jmcatamney/gpdb,janebeckman/gpdb,yuanzhao/gpdb,pavanvd/postgres-xl,greenplum-db/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,rubikloud/gpdb,ashwinstar/gpdb,rubikloud/gpdb,rubikloud/gpdb,zaksoup/gpdb,oberstet/postgres-xl,CraigHarris/gpdb,tpostgres-projects/tPostgres,50wu/gpdb,CraigHarris/gpdb,chrishajas/gpdb,yazun/postgres-xl,cjcjameson/gpdb,xinzweb/gpdb,kaknikhil/gpdb,rubikloud/gpdb,greenplum-db/gpdb,atris/gpdb,Quikling/gpdb,0x0FFF/gpdb,ashwinstar/gpdb,lintzc/gpdb,lpetrov-pivotal/gpdb,arcivanov/postgres-xl,lintzc/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,cjcjameson/gpdb,lintzc/gpdb,lisakowen/gpdb,chrishajas/gpdb,tpostgres-projects/tPostgres,royc1/gpdb,oberstet/postgres-xl,lisakowen/gpdb,xuegang/gpdb,ovr/postgres-xl,lpetrov-pivotal/gpdb,lpetrov-pivotal/gpdb,ahachete/gpdb,50wu/gpdb,foyzur/gpdb,janebeckman/gpdb,xinzweb/gpdb,Quikling/gpdb,zeroae/postgres-xl,adam8157/gpdb,techdragon/Postgres-XL,xuegang/gpdb,chrishajas/gpdb,lisakowen/gpdb,adam8157/gpdb,randomtask1155/gpdb,ovr/postgres-xl,ovr/postgres-xl,ahachete/gpdb,Quikling/gpdb,ahachete/gpdb,yazun/postgres-xl,techdragon/Postgres-XL,Quikling/gpdb,janebeckman/gpdb,chrishajas/gpdb,oberstet/postgres-xl,kaknikhil/gpdb,greenplum-db/gpdb,xinzweb/gpdb,rvs/gpdb,xinzweb/gpdb,yuanzhao/gpdb,tangp3/gpdb,yuanzhao/gpdb,zeroae/postgres-xl,oberstet/postgres-xl,Chibin/gpdb,lisakowen/gpdb,janebeckman/gpdb,0x0FFF/gpdb,postmind-net/postgres-xl,greenplum-db/gpdb,zaksoup/gpdb,kmjungersen/PostgresXL,Quikling/gpdb,adam8157/gpdb,chrishajas/gpdb,lpetrov-pivotal/gpdb,rvs/gpdb,Postgres-XL/Postgres-XL,Quikling/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,adam8157/gpdb,lintzc/gpdb,CraigHarris/gpdb,0x0FFF/gpdb,oberstet/postgres-xl,xuegang/gpdb,Chibin/gpdb,xuegang/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,snaga/postgres-xl,snaga/postgres-xl,Quikling/gpdb,kmjungersen/PostgresXL,kmjungersen/PostgresXL,royc1/gpdb,kaknikhil/gpdb,zeroae/postgres-xl,royc1/gpdb,tpostgres-projects/tPostgres,rubikloud/gpdb,royc1/gpdb,xinzweb/gpdb,yuanzhao/gpdb,xinzweb/gpdb,xuegang/gpdb,lpetrov-pivotal/gpdb,arcivanov/postgres-xl,zaksoup/gpdb,edespino/gpdb,arcivanov/postgres-xl,Quikling/gpdb,janebeckman/gpdb,50wu/gpdb,randomtask1155/gpdb,rubikloud/gpdb,techdragon/Postgres-XL,rvs/gpdb,tangp3/gpdb,zaksoup/gpdb,Chibin/gpdb,tpostgres-projects/tPostgres,rubikloud/gpdb,pavanvd/postgres-xl,ahachete/gpdb,jmcatamney/gpdb,Quikling/gpdb,50wu/gpdb,postmind-net/postgres-xl,adam8157/gpdb,lintzc/gpdb,atris/gpdb,tangp3/gpdb,Chibin/gpdb,yazun/postgres-xl,adam8157/gpdb,yazun/postgres-xl,randomtask1155/gpdb,cjcjameson/gpdb,cjcjameson/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,adam8157/gpdb,zaksoup/gpdb,yuanzhao/gpdb,royc1/gpdb,Postgres-XL/Postgres-XL,edespino/gpdb,CraigHarris/gpdb,janebeckman/gpdb,Postgres-XL/Postgres-XL,ovr/postgres-xl,0x0FFF/gpdb,CraigHarris/gpdb,ashwinstar/gpdb,royc1/gpdb,Chibin/gpdb,lintzc/gpdb,greenplum-db/gpdb,atris/gpdb,yuanzhao/gpdb,foyzur/gpdb,yuanzhao/gpdb,atris/gpdb,zeroae/postgres-xl,snaga/postgres-xl,randomtask1155/gpdb,50wu/gpdb,jmcatamney/gpdb,foyzur/gpdb,xuegang/gpdb,xinzweb/gpdb,ahachete/gpdb,arcivanov/postgres-xl,lpetrov-pivotal/gpdb,cjcjameson/gpdb,zaksoup/gpdb,rubikloud/gpdb,edespino/gpdb,lintzc/gpdb,Chibin/gpdb,atris/gpdb,Chibin/gpdb,greenplum-db/gpdb,Postgres-XL/Postgres-XL,CraigHarris/gpdb,kaknikhil/gpdb,zaksoup/gpdb,lisakowen/gpdb,tangp3/gpdb,rvs/gpdb,lintzc/gpdb,ashwinstar/gpdb,Chibin/gpdb,pavanvd/postgres-xl,lpetrov-pivotal/gpdb,postmind-net/postgres-xl,atris/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,ovr/postgres-xl,jmcatamney/gpdb,kaknikhil/gpdb,arcivanov/postgres-xl,foyzur/gpdb,arcivanov/postgres-xl,0x0FFF/gpdb,cjcjameson/gpdb,kaknikhil/gpdb,xinzweb/gpdb,kaknikhil/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,0x0FFF/gpdb,snaga/postgres-xl,rvs/gpdb,royc1/gpdb,50wu/gpdb,ashwinstar/gpdb,atris/gpdb,0x0FFF/gpdb,edespino/gpdb,xuegang/gpdb,tangp3/gpdb,postmind-net/postgres-xl,kaknikhil/gpdb,rvs/gpdb,rvs/gpdb,chrishajas/gpdb,adam8157/gpdb,royc1/gpdb,janebeckman/gpdb,randomtask1155/gpdb,postmind-net/postgres-xl,kmjungersen/PostgresXL,CraigHarris/gpdb,lisakowen/gpdb,xuegang/gpdb,jmcatamney/gpdb,snaga/postgres-xl,tangp3/gpdb,tangp3/gpdb,janebeckman/gpdb,janebeckman/gpdb,ahachete/gpdb,foyzur/gpdb,randomtask1155/gpdb,ashwinstar/gpdb,rvs/gpdb,50wu/gpdb,edespino/gpdb,50wu/gpdb