sanlock: per command debug logging
Allow debugging logging for specific commands to be
enabled or disabled at the command processing level.
In sanlock.conf:
debug_cmd = +<name>
enables cmd level debugging for the named command.
debug_cmd = -<name>
disables cmd level debugging for the named command.
debug_cmd lines can be repeated, once for each name.
By default sanlock disables some cmds that are often
repetitive and fill the in-memory debug buffer.