Defined More App Routes

Defined a couple more endpoints for the API.  Now displays the available
resources for buses, trains and trams.  Also displays more complex relationships
between stops and routes and routes and stops.

Had to set the relationships between stops and routes with dynamic lazy loading
and no backref.  This was so that we can filter the many-to-many relationship
results.  Otherwise it's a InstrumentalList which we can't filter.