qemu: Add qmp_event_notification test

This case test QEMU Monitor Protocol Events.
It verifies if the appropriate qmp event
will be emitted when the required conditions
are met.

It tests the following events now:
RESET SHUTDOWN STOP RESUME WATCHDOG.

All tests follow the qmp commands:
system_reset, quit, system_powerdown.

Signed-off-by: Feng Yang <fyang@redhat.com>
config: Update qmp_event_notification config for rhel4 guest

RHEL4 guests need some special config to make this test work.

Signed-off-by: Feng Yang <fyang@redhat.com>