Always start neutron services

https://bugzilla.novell.com/show_bug.cgi?id=859678
Split common_install recipe in two recipes

We now have common_config (which generates the config files) and
common_agent (which is used for everything related to linuxbridge/ovs
agent).
Do not create sudoers file on SUSE

It's already packaged.
Simplify server recipe by moving things out

All bits for a l3 role are moved to the new l3 recipe.

The code immediately restarting services after config changes moved to
post_install_conf since this is where it's needed.
Group ovs code paths together
Try to not restart services in post-install if they were already started
Only mark neutron-server as to be restarted in post-install

We don't need the other services to create our network resources.
Create a l3 role

We can now have a real network node, separate from the API server.
Use correct permissions when creating /etc/neutron/plugins/cisco
Merge pull request #49 from vuntz/reorg

Code reorganization and split l3 role out of neutron-server