* Some visual ordering fixes for the item menu, plus a #define-toggleable option for the bottom right slot to be traversable for ease-of-use purposes (even if it doesn't do anything).
* Shield Drop...
* Whatever you've got orbiting or trailing you, DROP THEM WHERE THEY STAND. (Except for the ghost sink. That one's OK.)
* Pops your Thunder Shield.
* Happens upon ANY hit, except for deathpits.
* HUD Drop...
* Also does the above, except for the Thunder Shield thing.
* If there's any item left in your item box, pop it out as a little hovering, rotating Minecraft item!
* You can pick up the Minecraft item by driving over it if your item box is sufficiently empty, or the item which is contained within it is of the same type.
* Happens upon Size Down and battle elimination.
* Can also be forced on with `cv_kartdebughuddrop on`!
* Some other random stuff.
* Fix a bunch of `a->scale = b`'s into `P_SetScale(a, b)` form, for maximum validity.
* Make K_CleanHnextList and K_UpdateHnextList one function, since they only differed by one continue clause (and the type of their input parameter).
* Allow shrunken players to pick up item boxes again.
* Fix MF_NOCLIPTHING. (Gonna pass this fix to vanilla when I get the chance, too.)
* Break NiGHTS a little through my machinations.
Sink would only spawn its trail ever if you threw it on a tic that was (leveltime % 4 == 0), because it called its action every 4 tics instead of every tic
A lot more similar to the code used for player wall bumping, and is much less likely for you to just... pass through the object if you keep trying hard enough.
Also, falling rocks get pushed aside by invinicible players with no resistance.
Sink shield that makes it double-press to use, gives the trailing item slowdown, and shows other people that you have it, but doesn't have any collision
- Fixed remaining instances where camera position would scale with the player instead of the level; the camera should almost 100% certainly not change now when you get Grown/Shrunk
- Reset camera when switching viewpoint, to make it not look *as* weird when switching after you've finished (needs tested)
