<Swing Dev> RFR: JDK-8258645: Bring Jemmy 1.3.11 to JDK test base

[Alexandre Iline]

Some changes to JSliderDemoTest: set a non-default driver and additional diagnostics

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Commit messages:
 - JDK-8258645: Bring Jemmy 1.3.11 to JDK test base

Changes: https://git.openjdk.java.net/jdk/pull/1831/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=1831&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8258645
  Stats: 123 lines in 9 files changed: 69 ins; 9 del; 45 mod
  Patch: https://git.openjdk.java.net/jdk/pull/1831.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/1831/head:pull/1831

PR: https://git.openjdk.java.net/jdk/pull/1831