V1 errors

See merge request KartKrew/Kart-Public!140

I'm faily certain this also fixes broken logic (g_game.c).

The truncation handling in this one spot is okay, but the compiler isn't smart
enough for it. I'm leaving it as a warning because I'd like to make a dedicated
function for handling snprintf truncation in the future.

This reverts commit 995edfb1.

V1 lua stuff

See merge request KartKrew/Kart!155

THIS SHOULD BE THE LAST TIME I SWEAR

Fix Post Processing in 64-bit Software 3P/4P

See merge request KartKrew/Kart!156

This reverts commit a2a63c5e.

Vid_BlitLinearScreen didn't make sure that it was actually meant to be copying the entire screen rows before doing it properly.

Spinout angle change when boosting

See merge request KartKrew/Kart!153

Make brakes stronger

See merge request KartKrew/Kart!154

(You may also be able to actually read that code too.)

Fixes stupid obvious mistakes and changes the prefcolor reset to item.

# Conflicts:
#	src/d_netcmd.c
#	src/r_main.c
#	src/v_video.c

Upstream merge of next

See merge request !139