Reword fsync and full_page_writes docs to be clearer about when to turn them off.
Reword fsync and full_page_writes docs to be clearer about when to turn
them off.

Josh Berkus, with slight wording changes by me.

ashwinstar/gpdb,jmcatamney/gpdb,50wu/gpdb,Postgres-XL/Postgres-XL,xinzweb/gpdb,zeroae/postgres-xl,pavanvd/postgres-xl,jmcatamney/gpdb,snaga/postgres-xl,50wu/gpdb,adam8157/gpdb,kmjungersen/PostgresXL,ashwinstar/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,pavanvd/postgres-xl,Postgres-XL/Postgres-XL,snaga/postgres-xl,yazun/postgres-xl,greenplum-db/gpdb,kmjungersen/PostgresXL,techdragon/Postgres-XL,kmjungersen/PostgresXL,greenplum-db/gpdb,zeroae/postgres-xl,adam8157/gpdb,50wu/gpdb,zeroae/postgres-xl,lisakowen/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,Postgres-XL/Postgres-XL,jmcatamney/gpdb,lisakowen/gpdb,snaga/postgres-xl,yazun/postgres-xl,oberstet/postgres-xl,zeroae/postgres-xl,adam8157/gpdb,techdragon/Postgres-XL,50wu/gpdb,adam8157/gpdb,pavanvd/postgres-xl,50wu/gpdb,ovr/postgres-xl,tpostgres-projects/tPostgres,50wu/gpdb,postmind-net/postgres-xl,snaga/postgres-xl,lisakowen/gpdb,ashwinstar/gpdb,xinzweb/gpdb,pavanvd/postgres-xl,postmind-net/postgres-xl,oberstet/postgres-xl,Postgres-XL/Postgres-XL,ashwinstar/gpdb,lisakowen/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,greenplum-db/gpdb,kmjungersen/PostgresXL,postmind-net/postgres-xl,ovr/postgres-xl,arcivanov/postgres-xl,50wu/gpdb,tpostgres-projects/tPostgres,ashwinstar/gpdb,tpostgres-projects/tPostgres,postmind-net/postgres-xl,arcivanov/postgres-xl,adam8157/gpdb,greenplum-db/gpdb,yazun/postgres-xl,oberstet/postgres-xl,lisakowen/gpdb,techdragon/Postgres-XL,arcivanov/postgres-xl,zeroae/postgres-xl,arcivanov/postgres-xl,yazun/postgres-xl,jmcatamney/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,xinzweb/gpdb,ovr/postgres-xl,adam8157/gpdb,arcivanov/postgres-xl,Postgres-XL/Postgres-XL,adam8157/gpdb,lisakowen/gpdb,greenplum-db/gpdb,50wu/gpdb,ovr/postgres-xl,xinzweb/gpdb,pavanvd/postgres-xl,xinzweb/gpdb,xinzweb/gpdb,adam8157/gpdb,lisakowen/gpdb,kmjungersen/PostgresXL,postmind-net/postgres-xl,snaga/postgres-xl,yazun/postgres-xl,lisakowen/gpdb,techdragon/Postgres-XL,oberstet/postgres-xl,tpostgres-projects/tPostgres,xinzweb/gpdb,greenplum-db/gpdb,ovr/postgres-xl,tpostgres-projects/tPostgres,arcivanov/postgres-xl,jmcatamney/gpdb