Test that messages in portal service 4xx responses are displayed.

+review REVIEW-5058
Update completed test coverage for unexpected content responses from plugin service.

+review REVIEW-5058
Handle plugin portal error responses that don't conform to the schema.

+review REVIEW-5058
formatting.
When using `java version` to determine java version, don't assume that first line states the version.

 Under some conditions diagnostic output is given before the version number.

 +review
Expand test time support for setting language to the full locale, and respect locale settings when finding a compatible daemon.

 +review REVIEW-5061