RFR: CODETOOLS-7902793: Fix IllegalMonitorStateException in JInternalFrameOperatorCloseTest

[Alexandre Iline]

What worked was to override setClosed(boolean) in JInternalFrame to not close the frame.

Also while inspecting the stack trace, I have discovered that the description is not passed down from JInternalFrameOperator.waitClosed()

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Commit messages:
 - CODETOOLS-7902793: Fix IllegalMonitorStateException in JInternalFrameOperatorCloseTest

Changes: https://git.openjdk.java.net/jemmy-v2/pull/4/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jemmy-v2&pr=4&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-7902793
  Stats: 95 lines in 3 files changed: 36 ins; 44 del; 15 mod
  Patch: https://git.openjdk.java.net/jemmy-v2/pull/4.diff
  Fetch: git fetch https://git.openjdk.java.net/jemmy-v2 pull/4/head:pull/4

PR: https://git.openjdk.java.net/jemmy-v2/pull/4