core: adding remote console related events

When users connect to the console, no event notification is available to
specify that it happened.

This patch adds two events:
1. SetVmTicket event - when the user initiated the session
2. ClientIp changed event - when the user connects (this event requires
having a guest agent installed on the guest)

Change-Id: Id345f413f83d82ef3a14fa35c1be7b65699d3298
Bug-Url: https://bugzilla.redhat.com/1039862
Signed-off-by: Oved Ourfali <oourfali@redhat.com>