RespondsToParent
================

Adds responds_to_parent to your controller to respond to the parent document of your page.
Make Ajaxy file uploads by posting the form to a hidden iframe, and respond with
RJS to the parent window.

Example
=======

Controller:
 
  class Test < ActionController::Base
    def main
    end
 
    def form_action
      # Do stuff with params[:uploaded_file]
        
      responds_to_parent do
        render :update do |page|
          page << "alert($('stuff').innerHTML)"
        end
      end
    end
  end
 
main.rhtml:
 
  <html>
    <body>
      <div id="stuff">Here is some stuff</div>
 
      <form target="frame" action="form_action">
        <input type="file" name="uploaded_file"/>
        <input type="submit"/>
      </form>
 
      <iframe id='frame' name="frame"></iframe>
    </body>
  </html>
  
