Update Cyclades quotas to count the size of the Volumes in the
'cyclades.disk' resources:

* Update server creation to count disk quota, not based on the server
  flavor, but on the newly created volumes (those volume which are in
  'CREATING' status)
* Update volume attach/detach server commands to pass a list of quotable
  volume changes
* Update snf-dispatcher to check if an unexpected Ganeti job changes the
  disks of an instance. Only disks from which the Synnefo is aware (and
  so the exist in DB as Volumes) are taken into account.
* Update quota reconciliation mechanism to count 'cyclades.disk' based
  on user volumes.