<AWT Dev> Review Request: 8046221 [TEST_BUG] Cleanup datatransfer tests

[Petr Pchelko]

Hello, AWT Team.

Please review the fix for the issue:
https://bugs.openjdk.java.net/browse/JDK-8046221
The fix is available at:
http://cr.openjdk.java.net/~pchelko/9/8046221/webrev/

During my datatransfer modularization work I've needed to run some tests, but all our datatransfer 
tests depend on desktop and fail due to some other bug in jigsaw.  So I've cleaned them up, 
opensourced a bunch of tests and moved other test to the correct locations.

The pass rate in 100% for normal build.

With best regards. Petr.