Porting further material datum features and improvements.

code/__DEFINES/_flags/_flags.dm

@@ -145,4 +145,19 @@ GLOBAL_LIST_INIT(bitflags, list(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 204
 /// If the thing can reflect light (lasers/energy)
 #define RICOCHET_SHINY			(1<<0)
 /// If the thing can reflect matter (bullets/bomb shrapnel)
-#define RICOCHET_HARD			(1<<1)
+#define RICOCHET_HARD			(1<<1)
+
+#define KEEP_TOGETHER_ORIGINAL "keep_together_original"
+
+//setter for KEEP_TOGETHER to allow for multiple sources to set and unset it
+#define ADD_KEEP_TOGETHER(x, source)\
+	if ((x.appearance_flags & KEEP_TOGETHER) && !HAS_TRAIT(x, TRAIT_KEEP_TOGETHER)) ADD_TRAIT(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL); \
+	ADD_TRAIT(x, TRAIT_KEEP_TOGETHER, source);\
+	x.appearance_flags |= KEEP_TOGETHER
+
+#define REMOVE_KEEP_TOGETHER(x, source)\
+	REMOVE_TRAIT(x, TRAIT_KEEP_TOGETHER, source);\
+	if(HAS_TRAIT_FROM_ONLY(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL))\
+		REMOVE_TRAIT(x, TRAIT_KEEP_TOGETHER, KEEP_TOGETHER_ORIGINAL);\
+	else if(!HAS_TRAIT(x, TRAIT_KEEP_TOGETHER))\
+	 	x.appearance_flags &= ~KEEP_TOGETHER

code/__DEFINES/_flags/item_flags.dm

@@ -52,3 +52,4 @@
 #define ORGAN_VITAL				(1<<4)	//Currently only the brain
 #define ORGAN_NO_SPOIL			(1<<5)	//Do not spoil under any circumstances
 #define ORGAN_NO_DISMEMBERMENT	(1<<6)	//Immune to disembowelment.
+#define ORGAN_EDIBLE			(1<<5)	//is a snack? :D