Renamed the getAttributes() and setAttributes() methods of TextView and FxTextArea to getSelectionFormat() and setSelectionFormat(), to match the spec.
Also, the contentWidth, contentHeight, horizontalScrollPosition, and verticalScrollPosition properties of TextView now implement binding using a PropertyChangeEvent, because this is what a Scroller expects. As part of this, I've moved the dispatchPropertyChangeEvent() utility method from GroupBase to UIComponent.
QE Notes: None
Doc Notes: None