Lua action userdata quickfix

See merge request STJr/SRB2Internal!196

# Conflicts:
#	src/d_main.c
#	src/m_menu.c
#	src/s_sound.c
#	src/sdl/sdl_sound.c

Music Code Cleanup

See merge request !278

Smashspike hotfix

See merge request STJr/SRB2Internal!197

# Conflicts:
#	src/nds/i_sound.c
#	src/r_data.c
#	src/sdl12/mixer_sound.c
#	src/sdl12/sdl_sound.c
#	src/win32ce/win_snd.c

Endgame code refactor

See merge request !297

Handle fix for SDL Mixer

See merge request !301

More accurate GIF delay

See merge request !276

No doubling texture heights plz

See merge request !296

MI's unimportant code cleanup

See merge request !295

I've voided this out on other sound interfaces than SDL Mixer ones because I'm both not sure whether they need it, and not sure how to make them work with it if they do.

Only real difference here is that CEcho messages will always be cleared when going to credits/evaluation, but that's hardly a loss tbh.

G_ExitLevel tweak: Use HU_ClearCEcho() instead of HU_DoCEcho(""), the latter causes an empty line to appear in log.txt

Remove "playerdeadview" variable; it's not been used for its stated purpose for who knows how long now

Besides rankings popping up when you die just sounds weird anyway, maybe I'm just used to SRB2 not doing it I guess

Remove unused ObjectPlace_OnChange prototype (from when Objectplace was a consvar, which it is not anymore)

Also corrected what appears to be a typo in some comments above?

(it's only set to 0 in software, and only ++'d in OpenGL, what kind of sense does that make?)

Translucency transparency transactions

See merge request STJr/SRB2Internal!195

# Conflicts:
#	src/Makefile
#	src/lua_script.c
#	src/p_user.c
#	src/sdl/i_system.c
#	src/v_video.c
#	src/w_wad.c

OpenGL FOF slope skewing

See merge request !283

Fix for Chicmunk's weird camera related crash

See merge request !284

Tiny fix so that joystick2 being closed can let the JoystickSubSystem close before game close.

See merge request !292