Tidied common settings
Reverted to default (sqlite) settings so all working.
Moved original settings to be common includes.
Tidied BASE_DIR/SITE_ROOT
Added settings/includes/secrets.py facility for site specific secret data that should not be in the repo.
Added settings/development.py
Simplified configuration and corrected debug_toolbar induced problem
Added required postgres database configuration
Added explicit debug toolbar setup
Added .gitignore so that secrets.py never gets added into the repo by accident.