<Swing Dev> RFR: 8198990 : Move SwingSet2 from closed to OpenJDK

[Phil Race]

Bug: https://bugs.openjdk.java.net/browse/JDK-8198990
Webrev: http://cr.openjdk.java.net/~prr/8198990/

SwingSet2 has always been in closed, mostly because of some
images that could not be moved to OpenJDK.

Due diligence has been done and replacements have been found.
This new version has already been reviewed internally.

I will be removing the closed version at the same time as pushing this.

-phil.