title: ImageField upload_to not working
body: <p>Hay guys, I'm using an ImageField to upload files, however when i add upload_to to the ImageField it doesnt append the directory to the MEDIA_ROOT</p>
  
  <pre><code>MEDIA_ROOT = '/Users/username/Django/site/assests/'
  
  picture = models.ImageField(upload_to='uploads')
  </code></pre>
  
  <p>i get an error saying </p>
  
  <pre><code>No such file or directory: u'/Users/username/Django/site/assests/2homemap.png'
  </code></pre>
  
  <p>Also the record added to the DB is just the file name (without the uploads)</p>
  
  <p>any ideas?</p>