Update sequence docs.
Update sequence docs.

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