Enables the combo blend mode for most colorable loadout gear.

-The most meaning the colorable uniforms, suits, gloves, shoes, headgear, earwear, and accessories.
-Only affects mob icons for now, the inventory/floor icons still in old blend.
-Sort of a framework for possible additional options to come.
-Also messed around with some other stuff such as adding on-ear icons to the rest of the flower pins and bows, and made the base icons for the beanies lighter than the middle gray they were.

code/game/objects/items.dm

@@ -80,6 +80,7 @@
 	var/list/sprite_sheets_obj = list()
 
 	var/toolspeed = 1.0 // This is a multipler on how 'fast' a tool works.  e.g. setting this to 0.5 will make the tool work twice as fast.
+	var/addblends // Icon overlay for ADD highlights when applicable.
 
 /obj/item/New()
 	..()