title: HTTP code to return for unsupported PATCH
body: <p>I am implementing a PATCH method on a dropwizard REST resource. 
  Currently only a subset of the properties of the resource an be patched. And currently only the replace operation can be fulfilled.</p>
  
  <p>Which HTTP code should I return if I see a <code>PATCH</code> request for a property/path that is not suppported? And what should I return if the unsupported <code>add</code> or <code>remove</code> operations are requested?</p>