Tidy up test.
Add more documentation.
Add .reset! to remove all entities from all repositories.
Add more tests.
Suppress test colour output via environment variable.
Add more tests.
Add configuration option for log filepath.
Use custom log file path if provided.
Fix path and add quit key information.
Add more documentation.
Update example apps to use new configuration DSL.
Remove MonoLogger.
Overhaul configuration: make log location customisable;

- Change Configuration to singleton class from module.
- Remove #detect_debug_mode, #detect_trace_mode and VEDEU_ environment variables.
- Rename #system_key_options to #system_keys.
- Set default log to /tmp/vedeu.log.
- Add ability to reset configuration.
- Add configuration to test_helper; will write to 'vedeu_test_helper.log'.
- Add missing require statements.
- Add more documentation.