[8u60] Request for approval: 8080137 Dragged events for extra mouse buttons (4, 5, 6) are not generated on JSplitPane

[Alexander Scherbatiy]

Hello,

Could you approve the direct backport of the fix to JDK 8u-dev.

The bug: https://bugs.openjdk.java.net/browse/JDK-8080137
The webrev: http://cr.openjdk.java.net/~alexsch/8080137/webrev.00/
The review thread: 
http://mail.openjdk.java.net/pipermail/awt-dev/2015-May/009398.html
The JDK 9 changeset: 
http://hg.openjdk.java.net/jdk9/client/jdk/rev/64c17cb355b1

Thanks,
Alexandr.