adding yaml loading support.

now we can load routes

$mapper = new Mapper(new \Alchemy\Component\Yaml\Yaml());
$mapper->loadFrom("fixtures/routes.yaml");

using a yaml struct like this:

----- file: routes.yaml -----

home_route:
    pattern: "/"
    defaults: {_controller: main, _action: index}

to_index_route:
    pattern: "/{_controller}"
    defaults: {_action: index}

complete_route:
    pattern: "/{_controller}/{_action}"
    defaults: {}

----- end file ---------------------

and mapping normally

print_r($mapper->match('/home/sample'));