mod2c, mgnuc.sh, ml.sh:
Add new grades fast.gc, reg.gc, etc. for conservative garbage
collection. Remove the --gc option from ml, since that information
is now part of the grade.
mgnuc.sh mod2c mod2init.sh:
Moved these scripts from the code directory to the scripts directory.
Changed mgnuc to use the MERCURY_C_INCL_DIR environment variable.
Changed mod2init to use MERCURY_MOD_LIB_DIR and MERCURY_MOD_LIB_MODS.
Changed ml to use MERCURY_C_LIB_DIR rather than MERCURY_CLIB_DIR.
ml.sh:
Link the library using a full pathname, so that you don't
need to set LD_LIBRARY_PATH at runtime.
Fix the tests for hostname so that they actually work.
ml.sh, mnl.sh:
A few minor changes.
For mnl, ensure that if the user specifies the standard library
modules on the command line, we only link in one copy of them.