New stone chip/tool textures.

Make the chip darker, like loose cobble it comes from instead
of smooth stone.  Also make the chip larger and sit lower in
stacks and on shelves (e.g. against wooden base) to make it look
better and easier to see.

Make tool tips correspondingly darker too.

mods/nc_stonework/chip.lua

@@ -8,6 +8,8 @@ local modname = minetest.get_current_modname()
 minetest.register_craftitem(modname .. ":chip", {
 		description = "Stone Chip",
 		inventory_image = modname .. "_stone.png",
+		wield_image = "[combine:16x16:0,2=" .. modname .. "_stone.png",
+		wield_scale = {x = 1.25, y = 1.25, z = 1.75},
 		sounds = nodecore.sounds("nc_terrain_stony")
 	})