These are hacks that can be removed when GAP is updated to better accomodate
GAP/MPI.

1.  src/gap.c  has an incomplete conditionalization.  One conditionalization
  adds the comment
  /* GAPMPI module   */
  but no actual C code.
2. src/streams.c:  This has been fixed in GAP.  I need to adapt GAP/MPI now.
  Thanks.  I had set up a variable:  GAPMPI_Last   inside READ().
  But now there's an official variable:  LastReadValueGVar
3. sysinfo.gap lacks a  CC=... declaration.
   I hack it up from GAParch=...-gcc.
   This would be easy to add into gap4b5/sysinfo.in
4. GAP's bin/@GAParch@/Makefile
  lacks certain make variables that GAPMPI needs to pass in
  (to say where libmpi.a is, where include library is, etc.
  I hacked up pkg/gapmpi/Makefile.in to get around this,
    but this would be more easily added by changing gap4b5/cnf/Makegap.in
