FELIX-4389 Add support for jaas.ranking to order LoginModuleFactory services.
   (Thanks Tobias Bocanegra for providing the patch)
   - For backwards compatibility support for service.ranking is retained
       if the jaas.ranking property is missing
   - Also consolidated the service property and configuration constants

git-svn-id: https://svn.apache.org/repos/asf/felix/trunk@1558854 13f79535-47bb-0310-9956-ffa450edef68