BZ #1148746: Assign DEFROUTE to vlan or bond

https://bugzilla.redhat.com/show_bug.cgi?id=1148746

VLANs and Bonds were getting filtered out of the DEFROUTE loop.
Explicitly add the gateway interface if it is a VLAN and/or Bond.
Merge pull request #103 from bcrochet/bz/1148746

BZ #1148746: Assign DEFROUTE to vlan or bond