Settings and logging tweaks

- Fixing syntax highlighting in Textmate / Sublime Text.
- Test settings only added conditionally now to help when pylytics is installed in editable mode by pip.
- The table name is included in a couple more logging statements.
- library/settings.py now uses the colour output definitions from library/log.py.
- Sentry no longer used if no Sentry settings are present. 
This is a weird thing with Textmate / Sublime Text syntax highlighting. If it's a lowercase r they highlight raw strings as if they're regular expressions. Using uppercase R just treats it as a raw string, and the syntax highlighting doesn't break.