Support for no key => value but just value in Collection

It is now possible to just add a value to the collection through the ->add() method. You can check if a value exists through the contains() method and you can remove a value from the collection by using the destroy method()
Use the Collection class for the Route filters

Add the getPattern() method for tests
A couple of tests for the Route class
Rename RouteCollection to Router

The name RouteCollection gives the indication that it is a Collection class, but it isn't. Also use the Collection class for the routes, prefixes and filters
Some tests for the Router class