Update psql docs for recent octal-only string behavior.
Update psql docs for recent octal-only string behavior.

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