Update 9.5 release notes through today.
Update 9.5 release notes through today.

Also do another round of copy-editing, and fix up remaining FIXME items.

adam8157/gpdb,adam8157/gpdb,ashwinstar/gpdb,xinzweb/gpdb,lisakowen/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,xinzweb/gpdb,lisakowen/gpdb,lisakowen/gpdb,jmcatamney/gpdb,adam8157/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,jmcatamney/gpdb,lisakowen/gpdb,lisakowen/gpdb,jmcatamney/gpdb,50wu/gpdb,jmcatamney/gpdb,greenplum-db/gpdb,xinzweb/gpdb,lisakowen/gpdb,lisakowen/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,adam8157/gpdb,adam8157/gpdb,50wu/gpdb,jmcatamney/gpdb,lisakowen/gpdb,xinzweb/gpdb,greenplum-db/gpdb,adam8157/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,adam8157/gpdb,50wu/gpdb,jmcatamney/gpdb,50wu/gpdb,adam8157/gpdb,ashwinstar/gpdb,50wu/gpdb,ashwinstar/gpdb,xinzweb/gpdb,50wu/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,greenplum-db/gpdb,xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,50wu/gpdb