Updating Django gitignore for various reasons

Removing:
- static/uploaded/**/* since there is no default
  for upload paths (configurable)
- *.mo because it's a best practice to keep them
  close to the po files and update before release
- *.pyc since that's covered by the Python gitignore file

Adding:
- local_settings.py because it's a best practice
  for Django projects (next to settings.py)