Improve behavior of \watch with non-tuple-returning commands.
Improve behavior of \watch with non-tuple-returning commands.

Print the command tag if we get PGRES_COMMAND_OK, and throw an error for
other cases.  Per gripe from Michael Paquier.

In passing, add an fflush(), just to be real sure the output appears
before we sleep.

yazun/postgres-xl,xinzweb/gpdb,techdragon/Postgres-XL,adam8157/gpdb,ashwinstar/gpdb,adam8157/gpdb,xinzweb/gpdb,greenplum-db/gpdb,oberstet/postgres-xl,adam8157/gpdb,Postgres-XL/Postgres-XL,lisakowen/gpdb,yazun/postgres-xl,50wu/gpdb,xinzweb/gpdb,techdragon/Postgres-XL,lisakowen/gpdb,50wu/gpdb,ovr/postgres-xl,pavanvd/postgres-xl,xinzweb/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,jmcatamney/gpdb,lisakowen/gpdb,adam8157/gpdb,ashwinstar/gpdb,lisakowen/gpdb,yazun/postgres-xl,adam8157/gpdb,greenplum-db/gpdb,lisakowen/gpdb,greenplum-db/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,zeroae/postgres-xl,oberstet/postgres-xl,xinzweb/gpdb,pavanvd/postgres-xl,jmcatamney/gpdb,ashwinstar/gpdb,zeroae/postgres-xl,Postgres-XL/Postgres-XL,50wu/gpdb,lisakowen/gpdb,yazun/postgres-xl,ovr/postgres-xl,pavanvd/postgres-xl,lisakowen/gpdb,zeroae/postgres-xl,ovr/postgres-xl,50wu/gpdb,oberstet/postgres-xl,xinzweb/gpdb,50wu/gpdb,ashwinstar/gpdb,ashwinstar/gpdb,Postgres-XL/Postgres-XL,techdragon/Postgres-XL,adam8157/gpdb,adam8157/gpdb,greenplum-db/gpdb,50wu/gpdb,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,oberstet/postgres-xl,xinzweb/gpdb,jmcatamney/gpdb,yazun/postgres-xl,oberstet/postgres-xl,lisakowen/gpdb,xinzweb/gpdb,greenplum-db/gpdb,ashwinstar/gpdb,ovr/postgres-xl,ashwinstar/gpdb,jmcatamney/gpdb,50wu/gpdb,greenplum-db/gpdb,jmcatamney/gpdb,pavanvd/postgres-xl,zeroae/postgres-xl,greenplum-db/gpdb,adam8157/gpdb,techdragon/Postgres-XL,Postgres-XL/Postgres-XL,zeroae/postgres-xl,jmcatamney/gpdb,50wu/gpdb,ovr/postgres-xl,ashwinstar/gpdb