- also ship README.SUSE.packaging as source

- Replace manually defined macros to enable/disable different
lisp bindings with %bcond_with(out) macros.
- Improve dependency resolution between the different lisp
versions of maxima_exec by using Supplements: packageand()
appropriately.
- Enable sbcl compiled binaries and package it (needed for
maxima-jupyter).
- Enable mathjax support for installed html manual (pass
--enable-mathjax to configure).
- Add Requires: rlwrap to maxima, needed for rmaxima.
- Add Suggests: maxima-exec-sbcl to maxima to weakly recommend a
specific flavour of maxima in case the user doesn't specify one
during installation.
- Add README.SUSE.packaging documenting the packaging changes that
will be needed for pkgs depending on maxima.