-Hoops are spawned in P_SpawnHoop
-Item patterns are spawned in P_SpawnItemPattern
-Ring-like items are spawned normally via P_SpawnMapThing
-Bonus time items are spawned via P_SpawnBonusTimeItem, which is a wrapper for P_SpawnMapThing

Replaced functions for spawning premade rows of rings with a function for spawning a generic row of rings (groundwork for UDMF)

Turned nightsreplace into a macro so we have don't have to keep dragging it along as a function parameter

Made a mapthing-independent version of P_GetMobjSpawnHeight so P_SpawnHoopsAndRings subfunctions can use it instead of duplicating code.

P_SpawnMapThing(): Separated the giant post-Lua hook switch-case statement into its own function, and separated some of the larger cases into their own function as well

Make both NiGHTS hoop types use the same spawning code.

See merge request STJr/SRB2!560

Flats in walls

See merge request STJr/SRB2!548

Fix super theme ending early if invincibility expired

See merge request STJr/SRB2!559

Fix pflags not being properly reset when entering dust devil from top

See merge request STJr/SRB2!556

(UDMF prereq.) Map data lump interface

See merge request STJr/SRB2!535

# Conflicts:
#	src/p_setup.c

# Conflicts:
#	src/p_mobj.c

As a result, the old generic hoops now use 24 sprites instead of 32.

Better Deadzones

See merge request STJr/SRB2!541

Choose a random port as a client

See merge request STJr/SRB2!554

Don't uncurl from spin if Elemental Stomp is used

See merge request STJr/SRB2!555

This reverts commit 2a9a2c0f.

If you ever need to, you can change the client port number.