Tile change now triggers lighting engine #11

Tile change is used primarily by the chunkUpdate() and if water is
cascading it will cause many lighting updates.

src/com/github/jleahey/minicraft/World.java

@@ -159,6 +159,10 @@ public char removeTile(int x, int y) {
 
 	public void changeTile(int x, int y, Tile tile) {
 		tiles[x][y] = tile;
+		if (tile.type.lightBlocking > 0)
+			lightingEngine.addedTile(x, y);
+		else
+			lightingEngine.removedTile(x, y);
 	}
 
 	private char[] breakWood = new char[] { 'w', 'p', 'f' };