acu141082 static IP support for Ubuntu 12.04
acu141082 NAT routing support for Ubuntu 12.04
acu141082 don't save gateway in config if gateway is not provided
acu141082 persist routes to correct config file
acu141082 fix exception in default gw route existence check
Merge pull request #304 from rightscale/ivory_14_02_acu141082_ubuntu_12_04_support

Vscale Ubuntu 12.04 support