Allowing use of third party Routers to handle Routing.

A class alias has always been provided in applications/config/application.php, however it is never called as the Router class is always directly targeting the Laravel namespaced class.
Signed-off-by: Ben Corlett <bencorlett@me.com>

laravel/laravel.php

 <?php namespace Laravel;
 
+use Router;
+
 /*
 |--------------------------------------------------------------------------
 | Bootstrap The Framework Core
@@ -102,7 +104,7 @@ foreach (Bundle::$bundles as $bundle => $config)
 |
 */
 
-Routing\Router::register('*', '(:all)', function()
+Router::register('*', '(:all)', function()
 {
 	return Event::first('404');
 });
@@ -160,7 +162,7 @@ URI::$uri = $uri;
 |
 */
 
-Request::$route = Routing\Router::route(Request::method(), $uri);
+Request::$route = Router::route(Request::method(), $uri);
 
 $response = Request::$route->call();