R_GenerateBlendTables: allocate copy of palette for use in thread

Closes #504

See merge request KartKrew/Kart!1441

Fix Prisons death not ending the round + Spectator bool cleanup

See merge request KartKrew/Kart!1418

Only kills objectplace at map start, not general respawn

The solution in 67c2ae02 happens too late for K_TimeAttackRules

"Radius Action" thing type

See merge request KartKrew/Kart!1429

# Conflicts:
#	src/p_inter.c

SPRTINFO: print warnings instead of I_Error (don't crash the game)

See merge request KartKrew/Kart!1445

The palette can be freed while this thread is still
running, which means the thread would end up reading from
freed memory.

Remove Texture Filtering option from Hardware Options (resolves #614)

Closes #614

See merge request KartKrew/Kart!1432

Smoothlanding leniency (resolves #602)

Closes #602

See merge request KartKrew/Kart!1428

Sealed Stars: show text on the screen for loss conditions; improved titlecard cecho centering, splitscreen support

See merge request KartKrew/Kart!1404

Not needed in K_UpdateGrandPrixBots or
K_LoadGrandPrixSaveGame because P_SpawnPlayer takes
priority.

Fixes centering for cechos of only punctuation.

- V_TitleCardStringWidth no longer has the special case
  for punctuation, moved to this function instead.
- Handles both leading and trailing punctuation, and even
  spaces.

toaster-assisted, thank-you-toaster

debugstart can now force POSITION on (resolves #600)

Closes #600

See merge request KartKrew/Kart!1431

Fix TextmapUnfixFlatOffsets & other writetextmap bugs

See merge request KartKrew/Kart!1437

More Sneaker Panels

See merge request KartKrew/Kart!1430

It had the right idea, it just literally did it wrong :P

Make -writetextmap a console command, call it "writetextmap"

See merge request KartKrew/Kart!1426

Pogospring / trickpanel disable fastfall (resolves #624)

Closes #624

See merge request KartKrew/Kart!1427

Makes resetting fastfall due to special conditions more
straightforward, because you don't need to reset
fastfallBase also.

No last-minute scams with Garden Top / Flame Shield (resolves #603)

Closes #603

See merge request KartKrew/Kart!1433

Fix Magician Box going crazy when player changed scale

See merge request KartKrew/Kart!1434