Hi Guix,

this patch continues the work done by Jeremy Robst to package HDF4

(https://lists.gnu.org/archive/html/guix-devel/2016-06/msg00069.html)

 - Back then, people reported occasional build failures. I've disabled
   parallel tests and don't have any problems on my system anymore
   (maybe someone else can test?).

 - I've added a patch to allow a shared build with Fortran interface,
   and some substitutions to remove bogus RPATH settings from the
   Makefiles (otherwise, build directories are included in the RPATH).

 - I've also added a variant “hdf4-alt”: by default, HDF4 includes a
   netCDF API to access HDF4 files, which clashes with the symbols in
   the real netCDF library when you try to use both libraries in your
   program.  This variant uses the “--disable-netcdf” configure flag
   to avoid this.  We could call it “hdf4-nonetcdf”, but the name
   “hdf4-alt” is used by Debian, so maybe it's good to use the same?

best,

Thomas