Fixed some issues with Sprite and TileSprite

lib/Sprite.js

@@ -4,6 +4,7 @@ class Sprite {
 		this.pos = { x: 0, y: 0 };
 		this.anchor = { x: 0, y: 0 };
 		this.scale = { x: 1, y: 1 };
+		this.pivot = { x: 0, y: 0 };
 		this.rotation = 0;
 	}
 }

lib/TileSprite.js

@@ -1,4 +1,5 @@
-var Sprite = require("./Sprite");
+var Sprite = require("./Sprite"),
+	AnimManager = require("./AnimManager");
 
 class TileSprite extends Sprite {
 	constructor(texture, w, h) {
@@ -6,6 +7,19 @@ class TileSprite extends Sprite {
 		this.tileW = w;
 		this.tileH = h;
 		this.frame = { x: 0, y: 0 };
+		this.anims = new AnimManager(this);
+	}
+  
+	update(dt) {
+		this.anims.update(dt);
+	}
+  
+	get w() {
+		return this.tileW * Math.abs(this.scale.x);
+	}
+  
+	get h() {
+		return this.tileH * Math.abs(this.scale.y);
 	}
 }