title: Symfony 1.4 - route by query string parameters
body: <p>Is it possible to route request to controllers/actions by query string parameters?
  And how to do it using routing.yml file?</p>
  
  <p>I mean:</p>
  
  <pre><code>/some/path?do=action1... 
  
  
  some_route:
      url: /some/path
      param: { module: module1, action: action1 }
      requirements:
          do: action1       &lt;--- ???
  
  
  /some/path?do=action2
  
  some_route2
     url: /some/path
     param: { module: module1, action: action2 }
     requirements:
          do: action2       &lt;--- ???
  </code></pre>
  
  <p>or some common route:</p>
  
  <pre><code>some_route:
      url: /some/path?do=:action
      param: { module: module1, action: action }
      requirements:
          do: action\d+       
  </code></pre>
  
  <p>Thanks!</p>