Allow to deploy Neutron API in WSGI with Apache.
Note: the feature is not tested yet in our functional testing jobs
because it doesn't work in devstack yet. This code will maybe need
some change but that's fine, it's for Pike cycle, nothing needs to be
backported, so we can easily iterate later.
Also remove dependencies in keystone auth manifest where keystone
resources had to be created before we start neutron-server. This is not
possible anymore since neutron-server is run in httpd.
Change-Id: I27bdd8d011097c5fd49277578404b4facafaca25
c1f019f8e1