title: checking if any Calendar Event/ Media Files got updated
body: <p>Am working on one of my requirement, halfway through am stuck on an issue. As per my requirement I need to know if any calendar event has been updated, say like any new participant is added or any event fields has been updated say Title,Description or location. As of now am able to know precisely if any event is added or deleted from system, but unfortunately am not able to detect out any update.</p>
  
  <p>The same scenario goes to media, i need to know if any fields related to a media is changed, say name,title or parent folder/path etc.</p>
  
  <p>to summaries my requirement is to know if any filed in Media or Calendar db is updated. to detect Insert or Delete am using Content Observers, as it only tells me something is changed by through onChange() call back, but it never tells you which rows was updated. </p>
  
  <p>regards,
  techfist</p>