easeljs: add decompose with no args

With no args, Matrix2D decompose returns a new object.

http://www.createjs.com/Docs/EaselJS/classes/Matrix2D.html#method_decompose

easeljs/easeljs-tests.ts

@@ -71,4 +71,11 @@ function test_canvas_tick() {
     var canvas = <HTMLCanvasElement>document.getElementById('canvas');
     var stage = new createjs.Stage(canvas);
     var stage = createjs.Ticker.addEventListener("tick", stage);
+}
+
+function matrixDecompose() {
+    var matrix = new createjs.Matrix2D();
+    var shape = new createjs.Shape();
+    var transform = matrix.decompose(shape);
+    var transform2 = matrix.decompose();
 }

easeljs/easeljs.d.ts

@@ -383,6 +383,7 @@ declare module createjs {
         appendTransform(x: number, y: number, scaleX: number, scaleY: number, rotation: number, skewX: number, skewY: number, regX?: number, regY?: number): Matrix2D;
         clone(): Matrix2D;
         copy(matrix: Matrix2D): Matrix2D;
+        decompose(): Matrix2D;
         decompose(target: Object): Matrix2D;
         identity(): Matrix2D;
         initialize(a?: number, b?: number, c?: number, d?: number, tx?: number, ty?: number): Matrix2D;