Add OS/X kernel tuning section.
Add OS/X kernel tuning section.

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