Just like the menu option

New engine sounds by VAda

See merge request KartKrew/Kart!38

Karmegg

See merge request KartKrew/Kart!36

(I've moved the comebacktimer set into one level up from that conditional; don't worry, I checked - there's nowhere that accesses this field while you have bumpers, it's just always set here for some dastardly reason.)

Sal cleanup

See merge request KartKrew/Kart!23

Fix the mixed declaration and code warnings

See merge request KartKrew/Kart!37

 - Volume of your own engine is lower than default
 - Engine sounds get quieter with more people around, ala SMK. 16 player servers should hopefully not be loud as fuck :V
 - Starting countdown and drop dash revs up your engine now
 - Doubled sound distance

9 unique engine classes with 13 sounds each, which smoothly change. Each character sounds distinct now!

Only covers things on P1's screen now

Noclip cam

See merge request KartKrew/Kart!32

Nuke a bunch of iteration things that have no purpose in SRB2Kart.

See merge request KartKrew/Kart!25

-skill launcher option

See merge request KartKrew/Kart!34

Fix the mixed declaration and code warnings that only don't appear currently because of a tiny Makefile issue.

# Conflicts:
#	src/p_inter.c

Frame Perfect Egg

See merge request KartKrew/Kart!31

Edit Pink, Navy, and Jet, add brown text

See merge request KartKrew/Kart!28

Droptweaks

See merge request KartKrew/Kart!27

Karma Eggman. Does what it says on the egg. Tried very hard not to merge conflict with `frameperfectegg`.

Also includes some adjustments to:
* Horizontal offset of Eggman countdown in splitscreen again. It's not perfectly centered either way, but on second thought I like this better.
* Sound of Lat`'s Mine/SPB explosions - now uses same sound as Karma bombing, instead of that shitty paraloop.
* Correctly wipe k_eggmanblame when it is appropriate to do so.