RFR: 8282633: jarsigner output does not explain why an EC key is disabled if its curve has been disabled

[Hai-May Chao]

When a named curve is disabled in `jdk.disabled.namedCurves` property which is included in `jdk.jar.disabledAlgorithms` and `jdk.certpath.disabledAlgorithms`, `jarsigner` should display the disabled named curve as a result of its disabled algorithm constraint checking. This clarifies why an EC key is disabled in its warning and verbose output.

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Commit messages:
 - remove tab in test
 - 8282633: jarsigner output does not explain why an EC key is disabled if its curve has been disabled

Changes: https://git.openjdk.java.net/jdk/pull/7810/files
 Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=7810&range=00
  Issue: https://bugs.openjdk.java.net/browse/JDK-8282633
  Stats: 137 lines in 5 files changed: 110 ins; 16 del; 11 mod
  Patch: https://git.openjdk.java.net/jdk/pull/7810.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/7810/head:pull/7810

PR: https://git.openjdk.java.net/jdk/pull/7810