13. core: Introducing EntityInfo class

EntityInfo will replace the EntityId at the parameters classes.

http://www.ovirt.org/Features/AsyncTaskManagerChanges_3.3
Change-Id: Ia591e05f2e27f43228a7b135ba82e7d7f46263d8
Signed-off-by: Yair Zaslavsky <yzaslavs@redhat.com>