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"