<AWT Dev> [9] Review Request: JDK-8030093 Generify DataTrasfer classes

[Petr Pchelko]

Hello, AWT Team.

Please review the fix for the issue:
https://bugs.openjdk.java.net/browse/JDK-8030093
The fix is available at:
http://cr.openjdk.java.net/~pchelko/9/8030093/webrev.00/

This is a general refactoring and clean-up for the DataTransferer class. Mostly generefication and replacing for with foreach.

With best regards. Petr.