Fix to include ml2 class groups and other needed mappings so

monolythic setup doesnt conflict with ml2.
Could these be uncommented by default?  If you're not using ml2 then the neutron::agents::ml2 classes never get called and therefore these just do nothing.  If you are using ml2 and we don't comment them out by default, that's one less thing for someone to configure to get their cloud up and running.