Allow pg_verify_checksums to specify a database to scan

When Who What
2018-10-02 02:44:55 Michael Paquier (michael-kun) Closed in commitfest 2018-09 with status: Returned with feedback
2018-09-01 06:19:46 Fabien Coelho (calvin) New status: Waiting on Author
2018-09-01 05:36:01 Fabien Coelho (calvin) Added calvin as reviewer
2018-08-31 11:07:57 Yugo Nagata (yugo.nagata) Changed topic to System Administration
2018-08-31 11:00:00 Yugo Nagata (yugo.nagata) Changed authors to Yugo Nagata (yugo.nagata)
2018-08-31 10:54:14 Yugo Nagata (yugo.nagata) Attached mail thread 7d5d3f34-ec64-602a-d7af-858eb686c86d@2ndquadrant.com
2018-08-31 10:54:14 Yugo Nagata (yugo.nagata) Created patch record