Added filling_color var to food items for use in sandwiches.

Conflicts:
	code/modules/reagents/reagent_containers/food/snacks.dm
	code/modules/reagents/reagent_containers/food/snacks/grown.dm
Icon fixes, shards hidden in food will now lacerate random body parts because damage code is weird. Stop eating chocolate cake sandwich with your left food.
Colour fix for bread slices.
Sandwich icon and dme fixes