scalafx.print: Some Spec Tests inactivated.

The Spec tests of classes with PrintResolution, JobSettings, PageLayout,
PrinterAttributes were throwing NullPointerException in Travis
environment. It happens because there is defined printer in this
environment. Since it is not possible to mock these classes (because
they are final) a provisory solution is simply inactivate their tests
until we can find a better solution.
scalafx.scene.web: Addedd missing 8.0 methods
scalafx.scena.web: Scaladoc improvements.

Also some classes received 'final' keyword to match with their JavaFX
counterparts.