remove unused db model for openvswitch plugin

remove unused TunnelIP db model.

fixes bug 1182759

Change-Id: I68c271019761e82a554c0d6c719b1689ef76eb98
Fix quantum.conf comment

Fixes bug 1183209

Change-Id: I87b47e5d5793fde0996712e05b4ddf12be07d3da
Merge "remove unused db model for openvswitch plugin"