title: assetic:dump --watch ignore changes on windows
body: <p>I would like to ask you about this problem. I'm using symfony 2.3 and I have problem witch assetic.</p>
  
  <p>If I run assetic:dump, everything works fine. But if I use --watch to rebuild after every change, it doesn't work. It does nothing. I'm working on windows.</p>
  
  <p>Has someone experiences with this problem? Really thanks.</p>