Currently when rogue script kills QEMU process (using TERM/INT/HUP
signal) it looks indistinguishable from system shutdown. Lets report
that QEMU was killed and leave some clues about the killer identity.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>