Skin fields visibility changed from protected to no modifier in Java9

[Wolfgang Zitzelsberger]

In some Skins (e.g. MenuButtonSkinBar, TabPaneSkin, TextFieldSkin) the 
visibility of protected fields has been changed so they can't be 
accessed any longer without reflection. Skin classes are public in Java 
9, that's fine - however, limiting visibility makes things even worse. 
Because of Jigsaw a user is now forced to add related "-add-opens" 
arguments.

Additionally, there is no way to access Modena resources because the 
package is not opened - see also 
https://stackoverflow.com/questions/45414557/modena-css-resource-loading-fails-on-java-9

I wonder why you are that restrictive?

- Wolfgang