title: emacs directory variables excluding particular subdir
body: <p>I have a project A which requires 2 spaces indentation, but it embeds another project in a subfolder B which uses 4 spaces.</p>
  
  <p>I have the following in A/.dir-locals.el:</p>
  
  <pre><code>((c-mode . ((indent-tabs-mode . nil)
              (c-basic-offset . 2))))
  </code></pre>
  
  <p>... and it nicely applies to all c files in directory A.</p>
  
  <p>Question: Can I in that same dir-locals.el file exclude the subfolder B from being affected by the 2 spaces indentation?</p>
  
  <p>I could of cause create a A/B/.dir-locals.el with the settings for B, but since it is A that is the exception right now, I would prefer to keep the setup in A/.dir-locals.el</p>