Fallback to RouteController for settings

(While fixing https://github.com/meteorhacks/fast-render/issues/84, I discovered a similar bug in handleRoute)

processRoutes() didn't look up the RouterController for a given route
correctly, and handleRoute() didn't consider the fact that if a route
doesn't declare a waitOn or a subscriptions, iron-router will use its
RouteController's waitOr or subscriptions