Adding mapfix mod

- Adding the mapfix mod to repair shadow-ed areas on a map (eg. after using worldedit).

Signed-off-by: LeMagnesium <mg.minetest@gmail.com>

mods/mapfix/init.lua

@@ -0,0 +1,19 @@
+minetest.register_chatcommand("mapfix", {
+	params = "<size>",
+	description = "Recalculate the flowing liquids of a chunk",
+	func = function(name, param)
+		local pos = minetest.get_player_by_name(name):getpos()
+		local size = tonumber(param) or 40
+		if size > 50 and not minetest.check_player_privs(name, {server=true}) then
+			return false, "You need the server privilege to exceed the radius of 50 blocks"
+		end
+		local minp, maxp = {x = math.floor(pos.x - size), y = math.floor(pos.y - size), z = math.floor(pos.z - size)}, {x = math.ceil(pos.x + size), y = math.ceil(pos.y + size), z = math.ceil(pos.z + size)}
+		local vm = minetest.get_voxel_manip()
+		vm:read_from_map(minp, maxp)
+		vm:calc_lighting()
+		vm:update_liquids()
+		vm:write_to_map()
+		vm:update_map()
+		return true, "Done."
+	end,
+})