core: Host's Compatibility Version doesn't match the
Cluster's Compatibility Version

If Engine sees itself in the supportedENGINES of a Vdsm
of an unknown version, and that Vdsm has the relevant
clusterLevel, Engine should believe it and take it into
the cluster.

As a result we also remove the SupportedVDSMVersions
parameter from vdc_options, as it is no longer needed

Change-Id: I1a899462ce3d74f3b1570a23c10ce38aeae1a18e
Bug-Url: https://bugzilla.redhat.com/1077110
Signed-off-by: lzelkha@redhat.com <lzelkha@redhat.com>