title: how to use svndumpfilter to exclude a certain revision
body: <p>I have an SVN repository with a bad revision or two. I need to get rid of them! I was planning on using the svndumpfilter tool, which has an <code>exclude</code> command. However, I cannot figure out how to use it to exclude a revision. Everytime I use it, I end up with a <code>Malformed dumpfile header</code> error. See the command below; I want to exclude revision 23, and code is the directory containing the repository.</p>
  
  <pre><code>&gt;svndumpfilter exclude 23 code
  Excluding prefixes:
     '/23'
     '/code'
  
  SVN-fs-dump-format-version: 2
  
  &lt;waits for me to type something and press enter&gt;
  
  'vndumpfilter: E140001: Malformed dumpfile header '
  </code></pre>