title: datastore count query fetchOptions
body: <p>I want to do the following:</p>
  
  <pre><code>PreparedQuery pq = datastore.prepare(q);
  int count = pq.countEntities(FetchOptions.ALL);
  </code></pre>
  
  <p>But there is no <em>ALL</em> option. So how do I do it?</p>
  
  <p>For context, say I want to count all entry in my table where color is orange.</p>
  
  <p>If I can't do this directly using <code>DatastoreService</code>, can I use <strong>Datanucleus's JPA</strong>? As in do they support <code>SELECT COUNT(*) ...</code> for the appengine datastore?</p>