JDK-8090930: Add Support for Extended Mouse Buttons

[Michael Ennen]

Hello All,

I am working on JDK-8090930 which is a request to add
support for the BACK/FORWARD mouse buttons that are
supported by some mice. I have opened a proof-of-concept
pull request on Github which can be found here:

https://github.com/javafxports/openjdk-jfx/pull/173

This is still in the early stages (no CSR has been created yet,
however there is a preliminary one in the comments on the
above Github issue) but Kevin wanted me to post a notification
to this list so that people can review and comment on it (and
I think that's a good idea, too).

Thanks,

Michael Ennen