Prevent spectate griefing

See merge request KartKrew/Kart!43

Singleplayer fixes (no, not record attack, the *other* one)

See merge request KartKrew/Kart!46

Sweet new kicks

See merge request KartKrew/Kart!39

Hard Mode is an unlockable

See merge request KartKrew/Kart!40

Remove most gameplay prints

See merge request KartKrew/Kart!42

Some token efforts to make singleplayer mode (accessible only via `-warp` and `map mapxx -force`) not COMPLETELY broken.

* Fixed the conditionals for `suicide` and `retry` commands - `suicide` is now allowed in singleplayer, and `retry` no longer checks your lives (for now).
* Disable the "traditional" level reload method (which `retry` tried to use), since it was completely broken with the other changes we've made. Mapchanges only.
* Made retries cause a mapchange, per the above.
* Disable the last source of skincolor trampling in the game - loading a level while not netgame or record attacking.

(Needs tested)

Fix "advancemap next" going to GHZ at the end of a cup

See merge request KartKrew/Kart!44

Next-merge plus rain

See merge request KartKrew/Kart!41

Engine tune-up

See merge request KartKrew/Kart!45

Now that we figured out that the sound cut-outs were due to a race condition and not this option, I feel content putting it with these other engine tweaks.

Minor priority change to two voice lines; the "passing someone" line has the same priority as every other line, and gave it's boosted priority to the way more gameplay-important "hit 'em" line.

Sryder's request

NOW this is good enough to ship

Plus, this is generally better, as a mod could let you unlock stuff "out-of-order"

If the player count dips below what was stored on the start of the last lap, then don't do time over so that someone can't just spectate at the end of a race out of rage. Y'all are assholes :V

More sensible `drawdist_precip_cons_t` maximum (slightly more conservative than Sryder's suggestion)

A couple of the extraneous ones (karma interactions, bumper stealing, lap start notifications) have been removed outright. The rest that I could think of have been changed to use CON_LogMessage, so that they still go into log.txt when rereading a fun chat session but not showing themselves in gameplay. Necessary gameplay prints, such as players being defeated or coming back in Battle, have been kept until there's a suitable replacement for them in the future.

* Multiplied rain speed by 3, per Oni's request.
* Disable weather density - force to 1 if weather draw distance, otherwise zero
* Move the ceilingpic check into a more convenient part of the weather spawning loop.
* `drawdist_precip_cons_t` - replaces "Infinite" with "None".
* Disable the lowest normal draw distance (256), given... both kart and srb2 are basically unplayable like that.
* Disable cv_drawdist_nights entirely.

# Conflicts:
#	src/d_netcmd.c
#	src/d_netcmd.h
#	src/g_game.c
#	src/p_floor.c
#	src/p_user.c
#	src/r_data.c
#	src/r_data.h
#	src/v_video.c

Handle fix for SDL Mixer

See merge request STJr/SRB2!301

More accurate GIF delay

See merge request STJr/SRB2!276

No doubling texture heights plz

See merge request STJr/SRB2!296

MI's unimportant code cleanup

See merge request STJr/SRB2!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.

Unlocks at 30 emblems, or 100 matches played

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)