[don't merge yet] Ckozak/multiorg hypervisors

PR for notes and collaboration

Design:
https://engineering.redhat.com/trac/Entitlement/wiki/HypervisorGuestIdChange

TODO:
*Test the multiorg esx scenario (hypervisor resource spec tests)
*Is there anything wrong with multiple cascade deletions?  I assume not because HypervisorId should be deleted if its org or consumer is deleted (if the org goes, the consumer should follow too)
*Should probably index HypervisorId on consumer_id.  Wouldn't hurt to add on on owner_id as well.