title: Access to custom filter from an Angular directive with isolate scope
body: <p>I've defined a custom filter and a directive with an isolate scope and I can't figure out why the directive has access to the custom filter when I haven't injected it into the directive module (I have injected it into the application module--see example). </p>
  
  <p>Are scoping rules for filters different than for other scope properties? Or is this the wrong framework to use when thinking about filters?</p>
  
  <p>Working example here: <a href="http://jsbin.com/IRogUxA/6/edit?html,js,output">http://jsbin.com/IRogUxA/6/edit?html,js,output</a></p>
  
  <p>Thanks in advance!</p>