VMT version

Virtual Machine Template verion introduced. It will allow us to track
number of saves user performed.

Verion will be incremented only when it is not explicity set during creating
new VMT.
save action
remove older VMT action
remove old VMT action triggered after VMT state changed to ACTIVE
set VMT version when it is copied from another CS
appliance type PUT triggers save action

Save action is triggered when `appliance_id` parameter is passed into
PUT appliance type request.
Version presented on VMT admin view
actions moved into app/actions dir
better name for finding VMT with source id at site
Merge pull request #16 from dice-cyfronet/save

Save operation