Update HISTORY for 7.4.
Update HISTORY for 7.4.

Neil Conway

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