Make the trie support the notion of HTTP Method.

The leaf nodes now contain a map of HTTP methods to the Routes.
The Recursive findRoute method has also been improved to make a better
use of the context object (previously called pstack)
Use the new HTTP Method aware Trie

Instead of one router per method, there is now one router that is
HTTP Method aware (thanks to the new Trie)

Thanks https://github.com/franckcuny for all the prototyping work !

This will allow smarter routing in the future and routing introspection.

Also note the router seems about 10% faster.