title: Defining a route in Symfony 2 with variable action
body: <p>Just imagine, I have a controller with several actions in it. 
  And to reach each action I have to define it strictly in routing.yml file like this:</p>
  
  <pre><code>admin_edit_routes:
      pattern:  /administrator/edituser
      defaults: { _controller: MyAdminBundle:Default:edituser }
  admin_add_routes:
      pattern:  /administrator/adduser
      defaults: { _controller: MyAdminBundle:Default:adduser }
  </code></pre>
  
  <p>And I can have plenty of such pages. What I want to achieve is to define necessary action in my URI, just like Kohana routes do.
  I mean, I want simply to use one route for all actions:
  (code below is not valid, just for example)</p>
  
  <pre><code>admin_main_route:
      pattern:  /administrator/{action}
      defaults: { _controller: MyAdminBundle:Default:{action} action:index}
  </code></pre>
  
  <p>It will pass all requests to /administrator/{anything} to this route, and after that, according to the action, stated in the uri, the needed action is gonna to be called.
  If action is not stated in the uri, then we got thrown to index action.</p>
  
  <p>Is it possible in Symfony 2 in any ways and if yes, then how?
  Thanking in advance.</p>