POC showing keystone running on Apache with mod_wsgi

Running python apps via shitty python web servers is painful. Running them behind
apache + mod_wsgi is much more interesting and provides some good apache style logs
for troubleshooting.

Since horizon is already using apache it was relatively simple to break the apache parts
out into their own role so that both horizon and keystone can utilize it.

I would love to look at using this for all of the openstack APIs and even look at using
mod_loadbalancer to replace haproxy,  I think this would be an excellent way to reduce the
complexity of our stack and provide something that the majority of devops^H^H^H^H^H^Hsystem
admins know how to use/troubleshoot in the form of apache.
So the mod_wsgi config needs to point at an "entry point" for the application. The configuration COULD point directly to the source of where keystone is installed, but since that varies from site to site they thought it best to instruct people to copy / link from their install into the cgi-bin/keystone/ directory. For our config, we could skip the copy / link and modify our config to point directly to where it is installed, but that might get interesting when we are dealing with upgrades.