[jdk8u-dev] RFR: 8029995: accept yes/no for boolean krb5.conf settings

[Alexey Bakhtin]

This fix solves regression caused by JDK-8139348 and found by the test suite of 3rd party library.
The fix allows to use "yes" and "no" values in the krb5.conf file. It is important because sometimes krb5.conf is autogenerated and uses "yes"/"no" values inside.
The backport is almost clean except of the Config.java file. Config.java already has some changes applied as part of JDK-8077102
sun/security/krb5 jtreg tests passed

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Commit messages:
 - Backport 9bae1e597b2d884e1d8a2a7a499b8d83ec002dbd

Changes: https://git.openjdk.org/jdk8u-dev/pull/367/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=367&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8029995
  Stats: 109 lines in 6 files changed: 75 ins; 25 del; 9 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/367.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/367/head:pull/367

PR: https://git.openjdk.org/jdk8u-dev/pull/367