title: Is there a Mercurial extension like svn propset?
body: <p>I need to attach custom metadata to my source files that at tracked via Mercurial.  The <a href="http://svnbook.red-bean.com/en/1.1/ch07s02.html" rel="noreferrer">svn properties</a> commands are exactly what I need.</p>
  
  <p>Is there a mercurial extension that provides commands similar to <code>propset</code>, <code>propget</code>, <code>propdel</code>, etc?</p>
  
  <p>If there isn't an extension, why not?<br>
  Is there an alternative/better approach for custom metadata when using Mercurial?<br>
  Is custom metadata not useful to anyone else?<br>
  Is the extension dearly desired but just not written yet?</p>
  
  <p><em>extra info</em>: If it helps.  The metadata I'm tracking is whether each file has been codereviewed, unittested, qa'd, etc.  This data needs to be traceable and merges between branches/clones aren't fine grained enough.</p>