Update config properties
- Update default config properties
Regarding logging level: 'verbose' and 'quiet' were no longer checked, instead there's now 'loglevel' integer which corresponds to spdlog::log_level enum values.
Boolean 'loop_enabled' was either misspelled all the way, or renamed in the main.cpp at some point in past.
- Warn about unrecognized configuration keys
Warn users about configuration keys that do not affect anything, despite what they might think. This is especially useful, since provided default configuration keys were changed / misspelled is past (see parent commit).