Rework maven configuration using YUM

@stdweird reported a successful configuration of Maven with YUM using the repo https://github.com/quattor/release/blob/master/src/scripts/build_all_repos.sh#L122. Should be used to provide a YUM-based Maven installation to replace the SPMA one (`cfg/standard/features/maven`).

When done, Maven should be optionally configurable in `rpms/quattor-development.pan` (`template-library-os`).
