ConfigTool: General Widget update

Fix #539

Tasks:
- [x] Update General widget look to match mock-up
- [x] Implement "Help us translate" button functionality
- [x] Implement "Reset to defaults" button functionality
- [x] Implement "Clear talks" button functionality (Removed after feedback)
- [x] Add confirmation dialog to both(?) reset buttons
- [x] Add translation code for new labels
Do you actually need a reference to this box in the future (i.e. outside of `__init__`)? If not then you probably shouldn't store it in the class instance.

This comment applies to other lines as well.