title: Disable caching for ExtJs app
body: <p>We have a ExtJS 5.01 app built with Sencha cmd 5.0.1.231. </p>
  
  <p>The issue we are facing is that browsers seem to cache the old version of our application. On looking at the network traffic on chrome when our application is served, i can see that app.js, app.css files all have ?_dc={timestamp} appended to them. Now, that tells me that every time a new version of my app is released (which updates this timestamp), the browsers should get a new version. But it seems like sometimes still the old version get served. </p>
  
  <p>Is there anything else i need to do bust cache?</p>
  
  <p>Thanks    </p>