RFR: JDK-8233636: Make jpackage an incubator and remove tool provider implementation

[Andy Herrick]

Please review the revised jpackage fix for bug [1] at [3].

This is a fix for the JDK-8200758-branch branch of the open sandbox 
repository (jpackage).

This webrev (webrev.03) addresses feedback from previous version 
(webrev.02).

[1] https://bugs.openjdk.java.net/browse/JDK-8233636

[2] https://cr.openjdk.java.net/~herrick/8233636/webrev.02

[3] https://cr.openjdk.java.net/~herrick/8233636/webrev.03

/Andy