Allow quantum core plugin to be passed through.

The openstack controller module didn't allow for a means to pass an alternate
core_plugin through to the quantum module.

Change-Id: I641091026f16e727689351329ffbabf14882516d
Reintroduce support for provider networks

There are two problems with provider networks:

First, the way bridge mappings are done
prevents users from having mutliple
provider networks. This patch allows
the user to pass them in directly.

Second, change 38426 proposes changing
the behavior of network_vlan_ranges
and this patch will reflect that by
passing down undef unless the user wishes
to override the defaults specified
in quantum::plugins::ovs

Change-Id: I36b11f9e0fa5458e50cbe59c8f4a5d1f3d9bdaa6
Merge "Allow quantum core plugin to be passed through."
Update the specification in openstack::keystone

This patch is aim to update the option names in specification
and the use example.

Change-Id: I5ae49b1a929cfeebe94dbf25435f8e3328fb8216
Merge "Reintroduce support for provider networks"