Fix saveHistory() to not emit bogus complaint during psql exit when using Darwin's libedit; per my proposal last August.  Also, suppress cast-away- const warnings.
Fix saveHistory() to not emit bogus complaint during psql exit when using
Darwin's libedit; per my proposal last August.  Also, suppress cast-away-
const warnings.

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