The service filter is a bit smelly

Look at a little refactoring on the service filter.

* The match methods are repetitive, maybe the service catalog should create a service filter. Then there could be one match method.
* The join method does seem like the right name
* The name ServiceFilter only describes one use.
* Maybe there should be some distinction between service identifiers and user preference. Should they be two different classes?
* If the service catalog creates some sort of service filter, should it be yet another class.
* Maybe the service filter should not be in the auth directory.