Remove old defaults system
Introduce priority-based fallback list
Use new functions for map_meta special functions
Change groups to use end tags
Unittest changes:
* Adapt unittest to the new code
* Compare Settings objects
- Add style properties for overriding the the hovered/pressed state
- By default, hovered buttons are a lighter version of the base color
- By default, pressed buttons are a darker version of the base color
- Add hovered bg image support for image buttons (style property)
Works by detecting a collision while moving forward and then
simulating a jump. If the simulated jump is more successful,
an artificial jump key press is injected in the client.
Includes setting and key change GUI element for enabling and
disabling this feature.
