Update devstack to handle Trove/Neutron setups
Update devstack to handle Trove/Neutron setups

Default Trove configuration (for task manager and service) don't
reflect the settings required for Neutron. Trove requires a
configuration that can only be done after neutron is up. This
introduces a new function called just before starting trove services.

Change-Id: I197ec2d3975f7b551590cf1f6c7d2cb42d479e25
Closes-Bug: #1435612

fabian4/trove,hplustree/trove,mmasaki/trove,mmasaki/trove,redhat-openstack/trove,zhangg/trove,cp16net/trove,fabian4/trove,fabian4/trove,cp16net/trove,cp16net/trove,redhat-openstack/trove,openstack/trove,redhat-openstack/trove,openstack/trove,mmasaki/trove,hplustree/trove,zhangg/trove