* Put everything in P_DoJumpStuff, instead of half in that function and half spread across the player thinker.
* Have a proper if else cascade that first tries shield abilities, then super transformation, then random abilities like CA_TELEKINESIS.
* Use this new arrangement to allow CA_TWINSPIN users to use their ability on spin if their secondary ability is CA2_MELEE (resolves#195).
* Random bugfixing. Didn't keep track of what I'd caused while working on this and what was already there, but there was a lot of it.
The only two abilities which have spin-button properties outside of the else block is CA_AIRDRILL and CA_FLY/CA_SWIM (which now also prevents you from swimming down in goowater).
* Don't allow the stage to be reloaded in G_DoReborn.
* If you do ANY spawn after the very beginning moment, you're forced to be a spectator.
* Have the "%d player%s remaining" Co-op exiting count visible at the same time as spectator controls.
* Genesis-style love and attention to the death event.
* Only visibly decrement lives/rings when you're respawning (or game over, see below).
* Faster no-button-press respawn.
* Game Over specific love.
* Animation of Level Title font coming in from the sides.
* https://cdn.discordapp.com/attachments/428262628893261828/617692325438554132/srb20067.gif
* Change gameovertics to 10 seconds instead of 15.
* Make the minimum time before you can force going to the Continue screen longer.
* Accomodate death in MP special stages as a form of exit.
* Don't have your rings or spheres reset when you die in a special stage, so that the stage isn't softlocked with the new harder limits.
* Fix a bug with CoopLives_OnChange where changing to infinite lives didn't force a game-overed player to respawn.
Also, two not-quite death things which nonetheless were relevant to change:
* Fix quitting a special stage having some of the shared spheres/rings disappear into the aether.
* Fix a warning during compilation for the Ring Penalty print.
