MODULE variable in makefiles limits module-definition refactoring

[Mark Reinhold]

(This is about Mandy's most recent changes in the TL forest, which are
 not (yet) in the Jigsaw forest.)

The use of the MODULE variable in many makefiles seems to tie those files
to the contents of modules.config and modules.group; i.e., if one of the
latter files changes then some MODULE definitions may also need to be
adjusted.  This will make it more difficult to experiment with, and
refactor, the module definitions.

To support changes in the modules.group file, at least, would it make
sense to enhance the class analyzer to generate another type of output
file, say foo.members, which for a grouped module lists its lowest-level
member modules?  Then the modularize target in the modules makefile could
copy the non-class contents of all the low-level modules into the
corresponding grouped module.

- Mark