New hammer utility feature in HEAD: 'hammer cleanup'

[Thomas Nikolajsen]

>I've added a meta-command to the hammer utility.  
>
>'hammer cleanup' will do the following:
>
> * Locate all mounted HAMMER filesystems, including PFS's mounted with
>   nullfs.

Nice!

It would be nice if hammer(8) included a command to list all PFSs
(maybe pfs-status without arguments);
this could be used for a general way to iterate PFSs.
Is this info saved in a HAMMER fs?

A few questions:
 - `hammer snapshot' is a per PFS operation, right?

 - Is null mounts the recommended way to use PFSs in general?

 - Is PFS #0 (the hammer fs) a fully functional PFS
(mirroring capable)?

 -thomas