Refs #547. Don't upgrade to jshint 2.5.0.

2.5.0 drops support for indentation/whitespace warnings,
which are very valuable to us.
Refs #547. De-linted to comply with jshint 2.4
Refs #547. Changelog entry
Merge pull request #547 from wymeditor/issue_547

JSHint ignores indentation since v2.5.0