java/junit: Update 4.12 => 4.13.2, take maintainership

Release Notes:
https://github.com/junit-team/junit4/blob/HEAD/doc/ReleaseNotes4.13.md
https://github.com/junit-team/junit4/blob/HEAD/doc/ReleaseNotes4.13.1.md
https://github.com/junit-team/junit4/blob/HEAD/doc/ReleaseNotes4.13.2.md

Improve port: replace PORTVERSION with DISTVERSION, add LICENSE, pet
portclippy and etc.

PR: 286465