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/assembly/assembly.dm

@@ -81,9 +81,9 @@
 /obj/item/assembly/process()
 	return PROCESS_KILL
 
-/obj/item/assembly/examine(mob/user)
+/obj/item/assembly/examine(mob/user, distance, infix, suffix)
 	. = ..()
-	if((in_range(src, user) || loc == user))
+	if(distance < 2)
 		if(secured)
 			. += "\The [src] is ready!"
 		else

code/modules/assembly/holder.dm

@@ -16,13 +16,13 @@
 /obj/item/assembly_holder/proc/attach(var/obj/item/assembly/D, var/obj/item/assembly/D2, var/mob/user)
 	if(!D || !D2)
 		return FALSE
-	
+
 	if(!istype(D) || !istype(D2))
 		return FALSE
 
 	if(D.secured || D2.secured)
 		return FALSE
-	
+
 	if(user)
 		user.remove_from_mob(D)
 		user.remove_from_mob(D2)
@@ -55,9 +55,9 @@
 	if(master)
 		master.update_icon()
 
-/obj/item/assembly_holder/examine(mob/user)
+/obj/item/assembly_holder/examine(mob/user, distance, infix, suffix)
 	. = ..()
-	if ((in_range(src, user) || src.loc == user))
+	if (distance < 2)
 		if (src.secured)
 			. += "\The [src] is ready!"
 		else

code/modules/assembly/mousetrap.dm

@@ -7,7 +7,7 @@
 	var/armed = 0
 
 
-/obj/item/assembly/mousetrap/examine(var/mob/user)
+/obj/item/assembly/mousetrap/examine(mob/user, distance, infix, suffix)
 	. = ..(user)
 	if(armed)
 		. += "It looks like it's armed."