General code and settings menu overhaul

[Moerill]

Its finally time to redo this whole module, by trying to add a bit more modularity and flexibility code wise.

Also a small settings menu overhaul is overdue, trying to adapt to the style used in my other modules, using FA checkboxes, etc. to make it look a tad more modern.

Some ideas, more like notes for myself:

• modular settings menu, let each "module" of the core module hook into it and provide the information that is needed to get the settings
  • For more unity on how stuff is supposed to look, streamline the way the settings menu is supposed to look. (And possibly make it usable like that for other modules as well, so i have one settings menu style for all modules)
• add localization support, finally!
• ...?