Added middleware to App, updated request, added a few basically empty middlewares

 + Updated Request so that it uses __set/__get methods, making it possible
   for middleware to add values to them, say cookies etc

 + Made App->middleware to check if the middleware exists, if not it will
   try \DHP_FW\middleware and \App\middleware

 + TODO : need to update tests to reflect middleware, also test the loading
   of the middleware