VMM.Library.animate(): don’t churn object copies

This avoids declaring an object unless we didn’t receive one

source/js/Core/Core/VMM.Library.js

@@ -452,8 +452,8 @@ if(typeof VMM != 'undefined') {
 			var _ease		= "easein",
 				_que		= false,
 				_duration	= 1000,
-				_att		= {};
-			
+				_att;
+
 			if (duration != null) {
 				if (duration < 1) {
 					_duration = 1;
@@ -473,9 +473,9 @@ if(typeof VMM != 'undefined') {
 			
 			
 			if (att != null) {
-				_att = att
+				_att = att;
 			} else {
-				_att = {opacity: 0}
+				_att = {opacity: 0};
 			}
 
 			if (VMM.Browser.features.css.transitions && !('scrollTop' in _att)) {