* Takes function(player, mo) input.
* Return TRUE for stating that yes, the player is in a state that can cause contact damage, do with that what you will.
* Return FALSE for stating that no, the player is weak and vulnerable and cannot cause contact damage, do with that what you will.
* Return NIL for allowing the function to continue regular operation.
Fills a different ideological niche than ShouldDamage - that's for determining whether damage dished between two objects should happen, this is for determining which way around damage should be dished when considering a player-object interaction.
Or, in other words, think of it as "ShouldDamage is whether damage that has been requested should be granted, for object-object interaction, while PlayerCanDamage is for whether global player properties should cause damage to enemies and monitors in the first place, like spinning, hammering or stomping."
* Move HUD text's anchoring to underneath STR instead of above Lives.
* Adjust chat position slightly, to take advantage of SRB2's HUD layout having less content towards the bottom (unlike Kart, where it has roughly equal).
* Fix Match emeralds not displaying while in tab rankings with all-seven invuln/shoes bonus active.
* Port across the additional colour translation maps, including mobj-level support for "colorized" objects.
* Make Fangboss and both Metal Sonic objects greyscale if, on spawn, there is a player in the game who is not a spectator whose skin is that character.
* Allow bosses with MF_GRENADEBOUNCE to opt out of the MF2_FRET colour-flashing tomfoolery, and give this flag to Fang.
* Like Kart, remove cv_precipdensity.
* Like Kart, replace "Infinite" draw distance value with "None".
* Better thinker with more return optimisation.
* Better placement of thinking in rendering, to avoid ceiling-mounted sprite glitches.
Handled by changing some defaults.
Untested, experimenting with Gitlab Web IDE as reconfiguring my build environment is likely to be a pain and I'd like to put that off as long as possible please
