engine: Numa feature entities

The entities define for NUMA support feature.
See http://www.ovirt.org/Features/NUMA_and_Virtual_NUMA for the
feature information.

Change-Id: Ifefade432e7955503980bdc6fc5d73ea32818a95
Bug-Url: https://bugzilla.redhat.com/1069303
Signed-off-by: Bruce Shi <xiao-lei.shi@hp.com>