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/game/objects/items/weapons/material/chainsaw.dm

@@ -113,9 +113,9 @@
 /obj/item/chainsaw/proc/get_fuel()
 	return reagents.get_reagent_amount("fuel")
 
-/obj/item/chainsaw/examine(mob/user)
+/obj/item/chainsaw/examine(mob/user, distance, infix, suffix)
 	. = ..()
-	if(max_fuel && get_dist(user, src) == 0)
+	if(max_fuel && !distance)
 		. += "<span class = 'notice'>The [src] feels like it contains roughtly [get_fuel()] units of fuel left.</span>"
 
 /obj/item/chainsaw/update_icon()

code/game/objects/items/weapons/material/gravemarker.dm

@@ -36,11 +36,11 @@
 			qdel(src)
 	..()
 
-/obj/item/material/gravemarker/examine(mob/user)
+/obj/item/material/gravemarker/examine(mob/user, distance, infix, suffix)
 	. = ..()
-	if(grave_name && get_dist(src, user) < 4)
+	if(grave_name && distance < 4)
 		. += "Here Lies [grave_name]"
-	if(epitaph && get_dist(src, user) < 2)
+	if(epitaph && distance < 2)
 		. += epitaph
 
 /obj/item/material/gravemarker/update_icon()
@@ -76,4 +76,4 @@
 		G.add_fingerprint(usr)
 		G.dir = user.dir
 		QDEL_NULL(src)
-	return
+	return

code/game/objects/items/weapons/material/whetstone.dm

@@ -10,7 +10,7 @@
 	w_class = ITEMSIZE_SMALL
 	var/repair_amount = 5
 	var/repair_time = 40
-	
+
 /obj/item/whetstone/attackby(obj/item/I, mob/user)
 	if(istype(I, /obj/item/stack/material))
 		var/obj/item/stack/material/M = I
@@ -40,7 +40,7 @@
 	var/sharpen_time = 100
 	var/uses = 0
 
-/obj/item/material/sharpeningkit/examine(mob/user, distance)
+/obj/item/material/sharpeningkit/examine(mob/user, distance, infix, suffix)
 	. = ..()
 	. += "There [uses == 1 ? "is" : "are"] [uses] [material] [uses == 1 ? src.material.sheet_singular_name : src.material.sheet_plural_name] left for use."
 
@@ -75,4 +75,4 @@
 			to_chat(user, "Not enough material to sharpen [M]. You need [M.w_class*2] [M.material.sheet_plural_name].")
 			return
 	else
-		to_chat(user, "You can't sharpen [W] with [src]!") 
+		to_chat(user, "You can't sharpen [W] with [src]!")