Resolve issue #399 in the silliest way possible: by having Brak be yeeted off the platform by an explosion at his feet, preventing the downed mech from being anywhere near the escape pod.
* Prevent an infinite quantity of Emeralds being spawned when P_GiveEmerald is called while a MP Special Stage is in session (resolves#347).
* Fix FuriousFox's ridiculous timer on special stage spawn (mentioned in the comments of the previous issue) by correctly marking spectator players in special stages as finished, and preventing the underflow.
* Expose this via additional upper-16-bits flags of A_FlickySpawn.
* Use this to make Snailers not spawn their flicky inside the wall they're attached to.
* Make the behaviour of Egg Capsules more consistent mechanically regarding the flicky spawning, using the above as one relevant element.
Make the wall transfer while spinning PF_SPINNING|PF_THOKKED. This:
* Prevents PF_MULTIABILITY players from using their ability after a wall transfer.
* Has a more specialised case which allows players to roll after having wall-transferred while spinning.
* (side effect) allows modders to apply PF_THOKKED any time for more controllable spinning.
* Tweaked to use new sprites.
* Jet fume behaves much closer to Lach's wonderful work.
* Instead of clobbering tracer to spawn powerup overlay, use hprev.
* Change timings. One second less to charge up, but two seconds less to spin them out.
* Remove terrible pinch overlay in favour of new dashmode-mimic flashing.
* Add an alternate DEMOMARKER for ending the Metal Recording on death, which kills the Metal object as well.
* Add some more relevant exceptions to the "most objects are removed when touching a deathpit" thing, primarily for the sake of ghosts and Metal playback.
* Add height changes to demos and Metal playback (to properly place thok aura relative to object).
* Fix followmobj recordings in reverse gravity (done via more strenuous flag setting + info height serialisation).
* Make RA ghosts fade in from start tic, and go colorized on their final one.
* Fix thok auras potentially doing bad things if they're set to MT_NULL.
* Add sprite change support to Metal playback.
* Re-enable some stuff I previously disabled for Metal recording/playback.
* Make ALL objects spawned with skins properly acknowledge that their spawnstate's frame is a sprite2, rather than just specific objects.
* Fix placement of Metal Sonic fume in reverse gravity.
* Since not backwards compatible with the previous test build, increment DEMOVERSION again. (Don't worry, we've got like 65524 more versions allowed before we run out of possible DEMOVERSIONs...)
