New BussTUC plugin and several utils and fixes.

Add BussTUCPlugin with support for BusTUC by IDI. Add jSoup-based website-retriever. Add utils for general purpose use. Clean some junk. Fix settings file not being generated if not existing.
This util is named UrlUtil because it can be extended with other tips and tricks for Urls for easy access. I would much rather have this in a separate util than to clutter the code with try catches that can be handled elsewhere and avoid indentation which further makes it harder to read the code. Taking a look at a lot of our current plugin codebase, we could use a lot more of method extraction to avoid indentation and simplify the readability.