Fix lb-vip does not get route to default gw

Previously when creating a lb-vip it would be created without
a default gw. This patch fixes that and adds unit tests to check
that route add is called if the subnet has a gateway_ip.

Fixes bug 1162626

Change-Id: I155749fa6d9c843fca87a73f3cf85720aac26cfa
blueprint cisco-single-config

Scope: Unification of all the various plugin files for the Cisco plugin into a single file.

Use Cases: Quantum with the Cisco plugin.

Implementation Overview: All the config values contained in the various files in
etc/quantum/plugins/cisco will be unified into a single file
etc/quantum/plugins/cisco/cisco_plugin.ini. The plugins needs to be modified to
read from a single file instead of multiple.
Added quantum.openstack.common.cfg support.

Change-Id: I9ef356eccfe330c3733f441b96400d03c3d7d1df
Merge "Fix lb-vip does not get route to default gw"