Acorn hologram & bug fix for eevee tails (#471)

* Edited Eevee wag code

fixes the issue where the tail tip color disappears while wagging

* Adds an acorn hologram

as the title says, adds an acorn hologram... it's animated too!

* Adds code to support the Acorn

allows an AI to select "acorn" from the unique hologram catagory

code/modules/mob/dead/new_player/sprite_accessories_Citadel.dm

@@ -258,6 +258,8 @@
 /datum/sprite_accessory/mam_tails_animated/eevee
 	name = "Eevee"
 	icon_state = "eevee"
+	extra = 1
+	extra_color_src = MUTCOLORS2
 
 /datum/sprite_accessory/mam_ears/fennec
 	name = "Fennec"

code/modules/mob/living/silicon/ai/ai.dm

@@ -705,7 +705,8 @@
 				"default" = 'icons/mob/AI.dmi',
 				"floating face" = 'icons/mob/AI.dmi',
 				"xeno queen" = 'icons/mob/alien.dmi',
-				"horror" = 'icons/mob/AI.dmi'
+				"horror" = 'icons/mob/AI.dmi',
+				"acorn" = 'icons/mob/AI.dmi'
 				)
 
 			input = input("Please select a hologram:") as null|anything in icon_list