Make use of openvswitch elements

Neutron and network-utils elements now depends of the new
openvswitch elements and delegate all openvswitch installation
and configuration into the openvswitch elements.

Closes-Bug: #1316985
Change-Id: Ib5c18e85317e6120b420d21790c26c21f4bbb0e4
Merge "Make use of openvswitch elements"