- add ghc-deps.sh for ghc package hash rpm metadata provides and requires
- turn on hash provides and disable debuginfo by default
- make shared and hscolour default
- use without_shared and without_hscolour to disble them
- add ghc_pkg_obsoletes for obsoleting old packages
- use ghcpkgbasedir
- always obsolete -doc packages, but keep -o for now for backward compatibility
