title: Last time the contact was modified
body: <p>is there a way to find out the last time a contact was modified?
  I can't seem to find a variable for it. The reason I'm asking is because I'd like to do a sync of the contacts to my web server and I don't feel like checking for each contact with a HTTP request if it needs updating.</p>
  
  <p>So I was thinking to check the date of the last update to the date of the last sync.</p>