Allows Prometheans to be cloned from their Core. (#4602)

* Allows Prometheans to be cloned from their Core.

* Swap brain cloning dependency from the cloner to the brain itself.

* Fffffff Changelog. And to_chat.

code/modules/organs/internal/brain.dm

@@ -13,6 +13,7 @@
 	throw_range = 5
 	origin_tech = list(TECH_BIO = 3)
 	attack_verb = list("attacked", "slapped", "whacked")
+	var/clone_source = FALSE
 	var/mob/living/carbon/brain/brainmob = null
 
 /obj/item/organ/internal/brain/robotize()
@@ -133,6 +134,10 @@
 	icon = 'icons/mob/slimes.dmi'
 	icon_state = "green slime extract"
 	parent_organ = BP_TORSO
+	clone_source = TRUE
+
+/obj/item/orgam/internal/brain/slime/is_open_container()
+	return 1
 
 /obj/item/organ/internal/brain/golem
 	name = "chem"