fixed new bug with stage toDataURL that was introduced with the new Canvas class, and added new filter unit tests

src/Shape.js

@@ -330,11 +330,10 @@ Kinetic.Shape = Kinetic.Node.extend({
             for(var n = 0; n < family.length; n++) {
                 var node = family[n];
                 var t = node.getTransform();
-
                 var m = t.getMatrix();
                 context.transform(m[0], m[1], m[2], m[3], m[4], m[5]);
             }
-
+            
             /*
              * pre styles include alpha, linejoin
              */