Gelencsér Szabolcs / circlestack

With network acl we need to add permission for that too

- node's default ordering is fine
- replacing "-" does not always work so fixed
    for example: ?sort=-na-me

dashboard, vm: implement remove_disk on InstanceTemplate and use it instead of dispatching on appliance type

Using datetime causes a RuntimeWarning because DateTimeField receives a naive
datetime while time zone support is active.