network: Make vdsmd addNetwork use supervdsmd setupNetworks

addNetwork is part of a very old and deprecated API that we have to
eventually shed off in the next major release. It makes sense to
just make an adapter so that we can simplify network.api to keep
a single entry point.

Change-Id: I5bc76dff5add1d29e8e14b86aea358de435a1997
Signed-off-by: Antoni S. Puimedon <asegurap@redhat.com>
Signed-off-by: Ido Barkan <ibarkan@redhat.com>
Reviewed-on: http://gerrit.ovirt.org/35090
Reviewed-by: Dan Kenigsberg <danken@redhat.com>