Issue #4 - Porting resize (micro/macro) systems.

* Instead of "playerscale" we are using pre-existing variable
 "size_multiplier" but we move it to /mob/living
* Added basic mechanics of size changing.
* Mousetraps snap small people even if they have shoes.
* Big people can walk over small people, or stomp them, or capture them
 in foot slot.
* Ported holder for micros, making small people scoopable.
* Tied held micros in with the vore code so they are edible.
* Ported size-altering reagents and recipies.
* Ported size gun along with associated sprites and sounds.

code/_helpers/global_lists_vr.dm

@@ -1,3 +1,15 @@
+/**
+ * VOREStation global lists
+*/
+
+//stores numeric player size options indexed by name
+var/global/list/player_sizes_list = list(
+		"Macro" 	= RESIZE_HUGE,
+		"Big" 		= RESIZE_BIG,
+		"Normal" 	= RESIZE_NORMAL,
+		"Small" 	= RESIZE_SMALL,
+		"Tiny" 		= RESIZE_TINY)
+
 //Important items that are preserved when people are digested, cryo'd, etc.
 var/global/list/important_items = list(
 		/obj/item/weapon/hand_tele,
@@ -60,4 +72,4 @@ var/global/list/struggle_sounds = list(
 		"Squish1" = 'sound/vore/squish1.ogg',
 		"Squish2" = 'sound/vore/squish2.ogg',
 		"Squish3" = 'sound/vore/squish3.ogg',
-		"Squish4" = 'sound/vore/squish4.ogg')
+		"Squish4" = 'sound/vore/squish4.ogg')