SpriteSheet animations loop by default.

Signed-off-by: Grant Skinner <info@gskinner.com>

Author: gskinner

src/easeljs/display/SpriteSheet.js

@@ -261,7 +261,7 @@ var p = SpriteSheet.prototype;
 					anim.next = obj.next;
 					a = anim.frames = obj.frames.slice(0);
 				}
-				anim.next = (a.length < 2 || anim.next == false) ? null : (anim.next == true) ? name : anim.next;
+				anim.next = (a.length < 2 || anim.next == false) ? null : (anim.next == null || anim.next == true) ? name : anim.next;
 				if (!anim.frequency) { anim.frequency = 1; }
 				this._animations.push(name);
 				this._data[name] = anim;
@@ -388,4 +388,4 @@ var p = SpriteSheet.prototype;
 	}
 
 window.SpriteSheet = SpriteSheet;
-}(window));
+}(window));