core: support NUMA in oVirt Scheduler

Filter out hosts that cannot accommodate memory of pinned
virtual (guest) NUMA nodes within host's physical NUMA node.

Change-Id: I2b41e5ac9d633953dec7bfab5621ace8bb1b13cd
Bug-Url: https://bugzilla.redhat.com/1069303
Signed-off-by: Gilad Chaplik <gchaplik@redhat.com>