title: Common files in Mercurial
body: <p>We have a Mercurial repository with many projects, each resides in its own directory:</p>
  
  <pre><code>- Main Repo
    - Project A
    - Project B
    - ...
  </code></pre>
  
  <p>Each of the projects is self contained and must reside in it's own directory, but there are some common files that should be similar between projects.</p>
  
  <p>For example, some projects are websites, and they share a common javascript library we develop. When changing the library in one project, we would like it to change in other projects too, but the file must reside in each of the projects.</p>
  
  <p>I read about sub-repos but they don't seem a good solution for this.</p>
  
  <p>Is there a way to accomplish this in Mercurial?</p>