Exclude backup folder

The subfolder is not under version control, however, you can place another version controlled source here if needed

After this commit, only the top level static files folder is ignored, while apps may contain static files that can then be collected by django

add static root to settings, ignore static folder in .gitignore
add production deployment requirements to README
add production deployment instructions to README
change port in uwsgi config file

add settings_production to override certain development settings
add settings_secrets.py.sample to illustrate usage of production secrets