fix(directives): cssUrl in NgComponent

When `cssUrls` (plural) attribute was added to `NgComponent` annotation,  `cssUrl` (singular) attribute was apparently accidentally removed from body of `cloneWithNewMap` method. 
As a result, if `NgComponent` uses annotations to bind attributes (`NgTwoWay` etc.) and `cloneWithNewMap` is used, `cssUrl` is lost during creating of new object.  

Related to #418