* 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."

Instead of only performing a hook if the Lua Hook loop determines its type to be the one we want, actively continue through the loop if it's NOT. This optimisation was performed while preparing the following commit; I have generously split them out for less shitty commit-by-commit review.

They basically work now.

Signed-off-by: Nev3r <apophycens@gmail.com>

Remove mute boolean from playermsg hook, fix username stuff still being there, potential memory leaks, and added back the ip message.

# Conflicts:
#	src/lua_hook.h
#	src/lua_hooklib.c
#	src/p_user.c

# Conflicts:
#	src/lua_hook.h

# Conflicts:
#	src/lua_hook.h
#	src/lua_hooklib.c

Smiles follow-mobj initial support! Still using a Lua hook to follow closely behind, but now it doesn't need to be a generic thinkframe. Woo!

Also slightly edited P_XYMovement to properly check the mobj still exists before checking its eflags for MFE_SPRUNG, while I was at it

Generic mobj hooks are now run before mobjtype-specific mobj hooks, and player/linedef executor hooks now have their own lists

Keeping the lua_gettop(gL) thing, otherwise the player/reason values will be pushed once to the stack each for every hook. Thanks MonsterIestyn!

MobjThinker, MobjCollide and MobjMoveCollide hooks are now directly linked to the mobjtype they belong to, so you no longer iterate through all existing hooks.

Adding ShieldSpecial hook. (Activates under different circumstances to the JumpSpinSpecial hook, and can be used to cancel existing shield actions.)

Restructured things so nojumpdamage characters can use the elemental, bubblewrap and attract shields.

Add "damagetype" argument to functions for Lua hooks ShouldDamage, MobjDamage, MobjDeath and HurtMsg

(no actual SLOC changes)

Argh, I knew I was forgetting something! archFunc is the argument to be passed to the hooks, not tables!