title: Why #egg=foo when pip-installing from git repo
body: <p>When I do a "pip install -e ..." to install from a git repo, I have to specify #egg=somename or pip complains. For example:</p>
  
  <pre><code>pip install -e git://github.com/hiidef/oauth2app.git#egg=oauth2app
  </code></pre>
  
  <p>What's the significance of this "egg" string?</p>