[Monotone-debian] Purge not working for monotone-server

[Francis Russell]

One of the Debian build checking tools spotted that monotone-server no
longer deletes its key when purged. The script current just assumes that
the filename is the same as the key id, but this is no longer the case,
as 'mtn genkey' now also adds the hash to the filename.

This seems to be a choice between deleting $MTN_KEY.* which seems
dangerous, or trying to store the key's actual filename in a db which
seems error prone especially considering this would only work for newly
generated keys.

Any thoughts?

Francis