title: Symbol not found: _PQbackendPID with Django project
body: <p>Running on MAC os 10.6.8
  with postgresSQL installed, as well django - using python2.7
  Also installed psycopg2 and dj-database-url using pip in my virtual env
  And added these two lines to my setting.py:</p>
  
  <pre><code>import dj_database_url
  DATABASES = {'default': dj_database_url.config(default='postgres://localhost')}
  </code></pre>
  
  <p>Based on instructions for Heroku in:
  <a href="https://devcenter.heroku.com/articles/django#database_settings" rel="nofollow noreferrer">https://devcenter.heroku.com/articles/django#database_settings</a>
  When running:</p>
  
  <pre><code>python manage.py runserver
  </code></pre>
  
  <p>I am getting this error:</p>
  
  <pre><code>ImportError: dlopen(/Users.... venv/lib/python2.7/site-packages/psycopg2/_psycopg.so, 2): Symbol not found: _PQbackendPID
  Referenced from: /Users.... venv/lib/python2.7/site-packages/psycopg2/_psycopg.so
  Expected in: dynamic lookup
  </code></pre>
  
  <p>I kept searching for hours and tried all kind of thing including the advice on:
  <a href="https://stackoverflow.com/questions/6999105/mac-os-x-lion-psycopg2-symbol-not-found-pqbackendpid">Mac OS X Lion Psycopg2: Symbol not found: _PQbackendPID</a>
  to no avail.</p>
  
  <p>Wonder if anyone had such an issue and had any luck.</p>