adding dont_render method to controller

Adds don't render method to controller, this way you can use a method to control your application without the need of having a view.

for instance:

  #routes.coffee
    '/:area':
      to: "pages/show"
      at: "/pages/index"

  #pages.coffee
    show: ( which ) ->
      console.log which.area
      #do your stuff
      @dont_render()

Unfortunately i still didn't manage to write tests on this.