large update for simplified reworked revision of Packaging Guidelines
    
    - see https://fedorahosted.org/fpc/ticket/194 for discussion
    - move section and multiple library metamacros to new extra subpackage
    - packaging no longer depends on availability of shared libs
      so is same now for all primary and secondary archs: ie there is always
      a binary base library package
    - drop ghc_add_basepkg_file macro and ghc_exclude_docdir