engine: Adjust console ticket commands

This patch makes it possible to set console ticket for multiple graphics
devices (new approach uses updateDevice command). For older VDSMs,
setTicket command is used.

TODO FOR WHOLE TOPIC:
 - restapi
 - consider renaming DisplayType to VideoType (it makes sense, the only
   drawback is ~300 LOC patch).

Change-Id: Ib62c9e29349a58156cddba1ca039cf9b7f14e610
Signed-off-by: Frantisek Kobzik <fkobzik@redhat.com>
Bug-Url: https://bugzilla.redhat.com/1033547