title: How do I preserve tags when filtering a repository?
body: <p>Is there a way to move a repository, <strong>and all its tags</strong>, to be a subdirectory of another repository in an automated fashion?</p>
  
  <p>For reasons, a project was split into multiple repositories.  Now we see that wasn't such a hot idea and want to bring it back together again.  Submodules were considered, but they really are one project and we need to move a lot of files between them.</p>
  
  <p>Let's say we have repository A, B and C.  And we want one project with each of them as a subdirectory:</p>
  
  <pre><code>project/
      A/
      B/
      C/
  </code></pre>
  
  <p>That can be accomplished with <code>git-filter-branch --tree-filter</code>.  Done, no problem.  And it even does the branches correctly too, which was a pleasant surprise.</p>
  
  <p>The trouble is, A, B and C have tags, and they all need to be converted, too.</p>
  
  <p>Can this be automated?</p>