Lick: call snapshot-uninstall rather than snapshot-destroy.

Uninstall deletes all disks assocaited with the snapshot, rather than
just removing it from the xapi db.
Monitor rutherford
Monitor http on rutherford
Stop monitoring yousense with nagios as it is not being used any more and is shut down
Merge branch 'master' of monitor.dtg.cl.cam.ac.uk:/etc/puppet-bare