title: How to use two collections to authenticate zfcuser?
body: <p>I use Doctrine and MongoDB ODM modules at my zf2 application. ZfcUser is used for authorization.</p>
  
  <p>Is there a way to use two collections, say <code>users</code> and <code>clients</code> to authenticate via zfcuser+doctrine? I am curious, if there is a way to combine two mongo collections into one to use combined for authentication? </p>