Add hardware node coloring. Includes:

- Increase ContentFeatures serialization version
- Color property and palettes for nodes
- paramtype2 = "color", "colored facedir" or "colored wallmounted"

src/minimap.h

@@ -52,10 +52,10 @@ struct MinimapModeDef {
 };
 
 struct MinimapPixel {
-	u16 id;
+	//! The topmost node that the minimap displays.
+	MapNode n;
 	u16 height;
 	u16 air_count;
-	u16 light;
 };
 
 struct MinimapMapblock {