title: Emacs VCS interface commits only one file
body: <p>When I commit changes with Emacs' built-in VCS interface (I use it with Bazaar) it commits only one file - that's open in current buffer.
  So when I press C-c v v, enter message and C-c C-c, it does something like</p>
  
  <pre><code>bzr commit -m "my message" file/open/in.buffer
  </code></pre>
  
  <p>instead of</p>
  
  <pre><code>bzr commit -m "my message"
  </code></pre>
  
  <p>How to commit all changes with Emacs?</p>