mcl_vegan_utils: create compression recipe util

create function for registering recipes that compress (and optionally
un-compress) items. an example of this in vanilla is wheat being
compressable into hay.

mcl_vegan_utils/craft.lua

@@ -0,0 +1,39 @@
+function mcl_vegan.register_compress_recipe (input, output, def)
+	def = def or {}
+
+	if def.reversible == nil then def.reversible = true end
+	local reversible = def.reversible
+
+	if def.big == nil then def.big = true end
+	local big = def.big
+
+	local compress_factor = 4
+	if big then compress_factor = 9 end
+
+	if big then
+		minetest.register_craft({
+			output = output,
+			recipe = {
+				{ input, input, input },
+				{ input, input, input },
+				{ input, input, input },
+			},
+		})
+	else
+		minetest.register_craft({
+			output = output,
+			recipe = {
+				{ input, input },
+				{ input, input },
+			},
+		})
+	end
+
+	if reversible then
+		minetest.register_craft({
+			type = "shapeless",
+			output = input .. " " .. compress_factor,
+			recipe = { output },
+		})
+	end
+end

mcl_vegan_utils/init.lua

@@ -13,3 +13,4 @@ include("farming_node")
 include("farming_item")
 include("drops")
 include("food")
+include("craft")