title: Use another site-packages directory by default for setup.py install
body: <p>I embedded Python in an application. When the user installs a package or module via</p>
  
  <pre><code>{...}\myapp\python\python.exe setup.py install
  </code></pre>
  
  <p>the packages will be installed in</p>
  
  <pre><code>{...}\myapp\python\lib\site-packages
  </code></pre>
  
  <p>Is there any chance to use another directory instead <strong>by default</strong>?</p>