add a new runstate: RUN_STATE_GUEST_PANICKED

The guest will be in this state when it is panicked.

Signed-off-by: Wen Congyang <wency@cn.fujitsu.com>
Signed-off-by: Hu Tao <hutao@cn.fujitsu.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-id: 0255f263ffdc2a3716f73e89098b96fd79a235b3.1366945969.git.hutao@cn.fujitsu.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
