Largish package/spec cleanup fixing most issues from merge review (#226377)
        and then some:
    - spec / package (review) cleanups:
    - use find_lang instead of manually listing translations
    - remove useless rpm 3.x upgrade check from preinstall script
    - use Fedora recommended buildroot
    - don't include useless, ancient GPG keys
    - add rpm, db and file licenses to docs
    - use scriptlet dependency markers instead of PreReq
    - post scriptlet requires coreutils
    - main package doesn't require patch, rpm-build does
    - buildrequire doxygen once more to resurrect apidocs
    - remove useless/doubly packaged files from /usr/lib/rpm
    - fix bunch of file permissions