examine signature changed to include distance

- distance is INFINITE, 0, or a positive integer based on get_dist() between
the examiner and examinee's turfs when they are on the same Z. When the
examiner is dead or a ghost, distance is always 0.
- also updates /examine( implementations to use it!
- adds w_class_to_name proc for reusing "It is a X item." examine behavior.

code/modules/persistence/graffiti.dm

@@ -37,7 +37,7 @@
 	SSpersistence.forget_value(src, /datum/persistent/graffiti)
 	. = ..()
 
-/obj/effect/decal/writing/examine(mob/user)
+/obj/effect/decal/writing/examine(mob/user, distance, infix, suffix)
 	. = ..()
 	to_chat(user,  "It reads \"[message]\".")
 

code/modules/persistence/noticeboard.dm

@@ -130,7 +130,7 @@
 /obj/structure/noticeboard/attack_hand(var/mob/user)
 	examine(user)
 
-/obj/structure/noticeboard/examine(var/mob/user)
+/obj/structure/noticeboard/examine(mob/user, distance, infix, suffix)
 	. = ..()
 	if(.)
 		var/list/dat = list("<table>")

code/modules/persistence/specimens.dm

@@ -36,7 +36,7 @@
 	to_chat(usr, "You set the tracker tag to '[tag_id]'.")
 	return TRUE
 
-/obj/item/specimen_tagger/examine(mob/user)
+/obj/item/specimen_tagger/examine(mob/user, distance, infix, suffix)
 	. = ..()
 	. += "Use this on a living animal on help intent to read an existing tracker, grab intent to tag an animal with a tracker, and any other intent to remove an existing tracker."
 
@@ -226,7 +226,7 @@
 	return
 
 // Mob helpers/overrides.
-/mob/living/examine(mob/user, infix, suffix)
+/mob/living/examine(mob/user, distance, infix, suffix)
 	. = ..()
 	var/obj/item/gps/specimen_tag/xenotag = locate() in src
 	if(istype(xenotag) && xenotag.has_been_implanted())