RFR: 8273634: [TEST_BUG] Improve javax/swing/text/ParagraphView/6364882/bug6364882.java

[Alexey Ivanov]

The test is being moved from the closed to open.

I updated the `bug6364882.java` test so that it's headless now. If it fails, the image of the `editorPane` is saved for analysis. I also added more asserts which verify:

• the first three lines are aligned to the right edge;
• the fourth line isn't justified and its width is less than 3/4 of the width;
• the fifth and sixth lines have width less than that of the fourth line and have the same width.

There's an option to show the UI for visual inspection as well as to save the image even if the test passes; use `-show` and/or `-save` parameters to the test correspondingly.

[1] [JDK-6364882](https://bugs.openjdk.java.net/browse/JDK-6364882): Last line of a paragraph should not be justified

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Commit messages:
 - 8273634: [TEST_BUG] Improve javax/swing/text/ParagraphView/6364882/bug6364882.java

Changes: https://git.openjdk.java.net/jdk/pull/5661/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=5661&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8273634
  Stats: 239 lines in 1 file changed: 239 ins; 0 del; 0 mod
  Patch: https://git.openjdk.java.net/jdk/pull/5661.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/5661/head:pull/5661

PR: https://git.openjdk.java.net/jdk/pull/5661