- no longer set ALWAYS_USE_MPI in Makefile (was done by genmake2). - improve genmake2 checking for ALLOW_${PKG} in CPP_OPTIONS.h files (distingues    upper/lower case ; account for space between "#" and undef/define)
- no longer set ALWAYS_USE_MPI in Makefile (was done by genmake2).
- improve genmake2 checking for ALLOW_${PKG} in CPP_OPTIONS.h files (distingues
   upper/lower case ; account for space between "#" and undef/define)

altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h,altMITgcm/MITgcm66h