RFR: JDK-8090763/CSR JDK-8203409 - Make JavaFX Robot Part of JavaFX Public API

[Michael Ennen]

Hello all,

Please review an enhancement to move the private Robot API into
a new public javafx.scene.robot package. The internal
com.sun.glass.ui.Robot class is removed as a result. Applications and
test frameworks that reference this internal class will need to adapt to
the new public API.

Enhancement: https://bugs.openjdk.java.net/browse/JDK-8090763

webrev: This is being worked on in the OpenJFX GitHub mirror:
https://github.com/javafxports/openjdk-jfx/pull/36/commits

CSR: https://bugs.openjdk.java.net/browse/JDK-8203409

Thanks very much to Kevin for all his help in getting to this stage,
Michael Ennen