signing_dir should always be defined

the default is /root/.keystone_signing otherwise
filter_factory moved to keystone_client in grizzly
don't define a service if we're installing from packages
use the ceilometer cache_dir, not the nova one
SUSE specific apache2 locations
have an option for disabling the creation of an apache2 reverse proxy

I'm not sure why this is in the recipe in the first place? Plust it conflicts with dashboard.