title: How to reset the renderer javascript context in atom-shell
body: <p>In a standard browser, loading a new url will reset the javascript context. ie. all global variables, compiled functions and events will be cleared, and the browser will start with a clean slate.</p>
  
  <p>In atom-shell however, calling <code>mainWindow.loadUrl</code> will load the new html file, but it will keep the javascript context alive. And so variables that I would need deleted would just hang around. How can I tell atom-shell to wipe out the whole javascript context on the renderer side?</p>