Updated for security purposes

Trolling around the .ssh/auth keys, I found several ssh keys which
should no longer exist. The main reason is that we do not clean up
the file properly.  The "remove-key" script would only remove the
key that was present in the repo, so if it had changed prior, it
wouldn't be able to match up with any key that was already existing
on any server. It wasn't worth keeping.

The changes were to the "add-all-keys" was to back up the auth keys
on the server, then load a fresh set from our known list. Backing
up the previous file uses Logrotate & its associated config file
to backup up to 14 files.