vdsProxy pass calls to undefined methods to API and return msg/status

Currently, every API call to be made has to be appended to utils.py in
order to be accessible by vdsProxy instance, this patch removes this
need for calls where only status and msg return values are relevant and
therefore reducing code (and api) duplication

Change-Id: I84d1e696a5280402725223ecc87646a75ba60061
Signed-off-by: Martin Polednik <mpoledni@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/18417
Reviewed-by: Dan Kenigsberg <danken@redhat.com>