Optimize memory usage by eliminating/changing some lists

Ported from TG: Object armors are no longer defined in (unique) lists but rather datums that can be cached depending on their armor values.
Add LAZYSET define to lazily initialize a list then assigning a key to a value
Add alldirs2 global which is the same as alldirs except diagonals go first
Optimize mob memory by making alerts list lazy
Optimize obj/machinery memory by making use_log and settagwhitelist lists lazy
Optimize atom memory by not creating hud_list list for all atoms
Optimize turf memory by not creating footstep_sounds list for all turfs
Clean up code where possible

code/datums/armor.dm

@@ -0,0 +1,66 @@
+#define ARMORID "armor-[melee]-[bullet]-[laser]-[energy]-[bomb]-[bio]-[rad]-[fire]-[acid]"
+
+/proc/getArmor(melee = 0, bullet = 0, laser = 0, energy = 0, bomb = 0, bio = 0, rad = 0, fire = 0, acid = 0)
+  . = locate(ARMORID)
+  if (!.)
+    . = new /datum/armor(melee, bullet, laser, energy, bomb, bio, rad, fire, acid)
+
+/datum/armor
+	var/melee
+	var/bullet
+	var/laser
+	var/energy
+	var/bomb
+	var/bio
+	var/rad
+	var/fire
+	var/acid
+
+/datum/armor/New(melee = 0, bullet = 0, laser = 0, energy = 0, bomb = 0, bio = 0, rad = 0, fire = 0, acid = 0)
+	src.melee = melee
+	src.bullet = bullet
+	src.laser = laser
+	src.energy = energy
+	src.bomb = bomb
+	src.bio = bio
+	src.rad = rad
+	src.fire = fire
+	src.acid = acid
+	tag = ARMORID
+
+/datum/armor/proc/modifyRating(melee = 0, bullet = 0, laser = 0, energy = 0, bomb = 0, bio = 0, rad = 0, fire = 0, acid = 0)
+	return getArmor(src.melee + melee, src.bullet + bullet, src.laser + laser, src.energy + energy, src.bomb + bomb, src.bio + bio, src.rad + rad, src.fire + fire, src.acid + acid)
+
+/datum/armor/proc/modifyAllRatings(modifier = 0)
+	return getArmor(melee + modifier, bullet + modifier, laser + modifier, energy + modifier, bomb + modifier, bio + modifier, rad + modifier, fire + modifier, acid + modifier)
+
+/datum/armor/proc/setRating(melee, bullet, laser, energy, bomb, bio, rad, fire, acid)
+	return getArmor((isnull(melee) ? src.melee : melee),\
+					(isnull(bullet) ? src.bullet : bullet),\
+					(isnull(laser) ? src.laser : laser),\
+					(isnull(energy) ? src.energy : energy),\
+					(isnull(bomb) ? src.bomb : bomb),\
+					(isnull(bio) ? src.bio : bio),\
+					(isnull(rad) ? src.rad : rad),\
+					(isnull(fire) ? src.fire : fire),\
+					(isnull(acid) ? src.acid : acid))
+
+/datum/armor/proc/getRating(rating)
+	return vars[rating]
+
+/datum/armor/proc/getList()
+	return list("melee" = melee, "bullet" = bullet, "laser" = laser, "energy" = energy, "bomb" = bomb, "bio" = bio, "rad" = rad, "fire" = fire, "acid" = acid)
+
+/datum/armor/proc/attachArmor(datum/armor/AA)
+	return getArmor(melee + AA.melee, bullet + AA.bullet, laser + AA.laser, energy + AA.energy, bomb + AA.bomb, bio + AA.bio, rad + AA.rad, fire + AA.fire, acid + AA.acid)
+
+/datum/armor/proc/detachArmor(datum/armor/AA)
+	return getArmor(melee - AA.melee, bullet - AA.bullet, laser - AA.laser, energy - AA.energy, bomb - AA.bomb, bio - AA.bio, rad - AA.rad, fire - AA.fire, acid - AA.acid)
+
+/datum/armor/vv_edit_var(var_name, var_value)
+	if (var_name == NAMEOF(src, tag))
+		return FALSE
+	. = ..()
+	tag = ARMORID // update tag in case armor values were edited
+
+#undef ARMORID