title: Difference between ContentObserver and DatasetObserver?
body: <p>What is difference between <code>ContentObserver</code> and <code>DatasetObserver</code>?</p>
  
  <p>When one or another should be used?</p>
  
  <p>I get <code>Cursor</code> with single row. I want to be notified about data changes - eg. when row is updated. </p>
  
  <p>Which observer class should I register?</p>