* Split z64.h more
* fix speedmeter.h (expect this kind of issue resolution to pop up eventually)
* fix z64object.h
* fix z64state.h
* fix (probably only partially) z64play.h
* fix fix speedmeter.h :)
* revert making a play header (sadge), add/split transition & transition_instances
* move stuff to cutscene, interface
* Move `TransitionCircle%` enums to `z64transition_instances.h`
* z64state.h -> z64game.h with a "this is not final" comment
* forward declare GraphicsContext in z64game.h instead of including the header file for it
* don't comment on where the forward declarations are from
reasoning:
1) it's easy to go out of sync (like this comment, it was outdated anyway)
2) any IDE can easily find the struct anyway
