Create veth peer in namespace.

 * Update veth pair creation to set the namespace of the peer
   device on creation rather than subsequently adding it to the
   namespace.
 * This change supports kernels with limited namespace support
   (e.g. RHEL 6.5) so long as ovs_use_veth is set to True.
 * Addresses bug 1171727

Change-Id: I1885acc9934e7627bb9872703df7f5edf2980722
Merge "Create veth peer in namespace."