Different default -fx-background-* value between css ref and getCssMetaData.

The default value "-fx-background-color" should be null , but has [Ljavafx.scene.paint.Paint;@
The default value "-fx-background-insets" should be null , but has [Ljavafx.geometry.Insets;@
The default value "-fx-background-insets" should be null , but has [Ljavafx.geometry.Insets;@
The default value "-fx-background-repeat" should be null , but has [Lcom.sun.javafx.scene.layout.region.RepeatStruct;@364a50f6
The default value "-fx-background-position" should be null , but has [Ljavafx.scene.layout.BackgroundPosition;@19638f92
The default value "-fx-background-size" should be null , but has [Ljavafx.scene.layout.BackgroundSize;@2fc2cd2c


http://jfx.us.oracle.com/hudson/view/8.0/job/8.0-controls-scrum/label=linux-amd64-30/ws/rt/modules/graphics/src/main/docs/javafx/scene/doc-files/cssref.html#region