title: In Mercurial, can obsolete changesets be forced to become not obsolete?
body: <p>In Mercurial changesets with a successor are marked <a href="http://mercurial.selenic.com/wiki/ChangesetEvolution" rel="noreferrer">obsolete</a>.</p>
  
  <p>Can this marker be (forcefully) removed somehow?</p>
  
  <p>After using <code>hg strip</code> to remove the successor, the original changeset is still marked as obsolete and extinct). <code>hg evolve</code> refuses to re-create the successor.</p>