This allows specific options in pgbackrest.conf to be ignored (and set to default) which reduces the need to write new configuration files for specific needs.
Note that boolean, non-command-line options are already negatable.
When a backup host is present, backups should only be allowed on the backup host and restores should only be allowed on the database host unless an alternate configuration is created that ignores the remote host.
Reported by Lardière Sébastien.
Required to test restores on the backup server, a fairly common scenario.
Improve the restore function to accept optional parameters rather than a long list of parameters. In passing, clean up extraneous use of strType and strComment variables.
If the backup cannot map a group to a name it stores the group in the manifest as false then uses either the owner of $PGDATA to set the group during restore or failing that the group of the current user. This logic was not working correctly because the selected group was overwriting the user on restore leaving the group undefined and the user incorrectly set to the group. (Reported by Jeff McCormick.)
The existing static files would not work with 32-bit or big-endian systems so create functions to generate these files dynamically rather than creating a bunch of new static files.
* Exclude contents of pg_snapshots, pg_serial, pg_notify, and pg_dynshmem from backup since they are rebuilt on startup.
* Exclude pg_internal.init files from backup since they are rebuilt on startup.
