Ceph

There are a bunch of monitor-specific commands that, from the user's perspective, have been kept as commands to the 'ceph' tool.

Examples of this would be:

- 'ceph scrub'
- 'ceph sync force'
- 'ceph compact'

While these make sense if they are preceded by a 'tell mon.X', using 'tell' is not at all required.

The reason for not having these commands under the 'mon' module has been because all commands under the 'mon' module will be handed over to the MonmapMonitor, and these commands are clearly out of the jurisdiction of the MonmapMonitor.

However, as it is I believe it's confusing, as it's not clear at all that these are monitor-specific commands, and I'm positive some users would assume they would have cluster-wide effects.

As such, I'm proposing moving these commands under the 'mon' module. Instead of blindly passing these commands to the MonmapMonitor, we should first check if the command being handled is any of these commands (on Monitor::handle_command()) and then dispatch to MonmapMonitor otherwise.