core: added is_run_once flag to vm_dynamic

Adds the is_run_once to vm_dynamic to be able to
find out about a VM if it is in run_once or not.

Change-Id: I25acdbcc84d326c694d7ae5ff1facaf13e5d683e
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=987985
Signed-off-by: Tomas Jelinek <tjelinek@redhat.com>