title: Easy way to override a sync value with backbone
body: <p>I have a number of models which are basically classes which never change.  They represent a number of settings for an object, and won't be changing.  Even if they do, I'll want to use the client's latest rather than the server values.  Rather than serializing the whole object, like it's doing now, I'd like to just instantiate the actual class freshly when backbone syncs.  What is the best way to accomplish this?</p>
  
  <p>Thanks</p>