title: Vim command for "edit a copy of this file"
body: <p>A pattern I seem to be following right now is:</p>
  
  <ul>
  <li>edit a file until I like it</li>
  <li><code>:w another-file</code> to use it as a starting point for <code>another-file</code></li>
  <li><code>:e another-file</code> to polish up <code>another-file</code></li>
  </ul>
  
  <p>Is there an existing ex command to do the latter two steps at once? Something like <code>:writeAndEdit another-file</code>?</p>
  
  <p>I can fake one using vimscript, I just want to know if there's an existing command.</p>