Add ovirt-node generic registration script

To replace vdsm-reg, put in place a generic registration script
which fulfills basic requirements so the engine can use otopi/
host-deploy

Change-Id: I9457b05716c4dc5a47a280b8335a41e6fae73c0d
Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=875088
Signed-off-by: Ryan Barry <rbarry@redhat.com>