Complete deletion when compute manager start-up.

Sometimes instances stay in DELETED state (vm_state) but are not
marked as deleted in the DB.
The combination of vm_state=DELETED and deleted=0 is a valid
combination but if we found it during the compute manager start-up that is
an indication that something went wrong while we were deleting an instance.
The aim of this change is just to complete the deletion during the compute
mangager start-up for instances found in that state.

bug 1187422
Change-Id: I52efa07b4d98106214fc54aee3af9de6eacb58d9
Merge "Complete deletion when compute manager start-up."