Remove duplicate from release notes, and reorganize slightly.
Remove duplicate from release notes, and reorganize slightly.

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