title: Discard all and get clean copy of latest revision?
body: <p>I'm moving a build process to use mercurial and want to get the working directory back to the state of the tip revision. Earlier runs of the build process will have modified some files and added some files that I don't want to commit, so I have local changes and files that aren't added to the repository. </p>
  
  <p>What's the easiest way to discard all that and get a clean working directory that has the latest revision?</p>
  
  <p>Currently I'm doing this: </p>
  
  <pre><code>hg revert --all
  &lt;build command here to delete the contents of the working directory, except the .hg folder.&gt;
  hg pull
  hg update -r MY_BRANCH
  </code></pre>
  
  <p>but it seems like there should be a simpler way.</p>
  
  <p>I want to do the equivalent of deleting the repo, doing a fresh clone, and an update. But the repo is too big for that to be fast enough.</p>