engine: watchdog - DB and logic changes

- DB scripts to add records to the vm record
  - last_watchdog_event the unix time from the host when the watchdog
    was triggered
  - last_watchdog_action the last action taken by the watchdog
- Vm and VmDynamic changes
- changes in commands
- vdsbroker changes

Change-Id: I813a6f97e23008d15446285998a4e9b50b456040
Signed-off-by: Laszlo Hornyak <lhornyak@redhat.com>