title: Load version of package for a given date in Pharo
body: <p>I am looking for a way to, given a package name, load a version of that package that was the newest version at a given date.</p>
  
  <p>For example:</p>
  
  <pre><code>HypotheticalClassLoader loadPackage: 'Athens-Core' onDate: ('12.03.2015' asDate).
  </code></pre>
  
  <p>Would load the first commit of 'Athens-Core' that is older than 12.03.2015.</p>