Issue 75

Fixes issue #75 .

Need alembic migration.

Needs libjpeg decoder if user uploads jpg files
```
pip uninstall PIL
sudo apt-get install libjpeg8-dev
sudo ln -s /usr/lib/x86_64-linux-gnu/libjpeg.so /usr/lib
pip install PIL
```

Ref: http://stackoverflow.com/questions/4632261/pil-jpeg-library-help