Cleans up the Keystone initializations

- Move all Keystone service and endpoint creation into the
keystone_init.sh script
- Remove all user, tenant, and role custom shell actions to use the
keystone_user Ansible module action
- Adds Apache site configuration for Keystone, controlled using a site
variable called "keystone_use_apache" (true by default)
Merge pull request #2 from jaypipes/keystone

Cleans up the Keystone initializations