New objects are created each time impl_cssSet is called causing performance problems.

In impl_cssSet in Labeled.java. The following snippet of code can cause performance problems because each time impl_cssSet is called a new ImageView is created. I fixed Labeled and Tooltip already but there may be other places in controls that have the same bug.

String imageUrl = (String)value;
if (imageUrl != null) {
    setGraphic(new ImageView(new Image(imageUrl)));
}