- add ghcdocbasedir
    - revert ghcdocdir to match upstream ghc
    - ghcdocdir and ghcpkgdir now take optional name version args
    - update ghc_gen_filelists to new optional name version args
    - handle docdir in ghc_gen_filelists
    - ghc_reindex_haddock uses ghcdocbasedir
    - summary and description options added to ghc_binlib_package,
        ghc_package_devel, ghc_package_doc, and ghc_package_prof