gumm hierarchy

[Thien-Thi Nguyen]

gumm hiearchy is inherently political.

a political system that is maximally useful allows its citizens to
define their desired demand on it, using a simple language.  in return,
the upkeep of the system must be light, and the rights of the citizens
must be codified and executed.

authors organize their modules in some personal way and use the module
system in some recognizably standard way, as they have always done,
since this is their right.  (so this part of gumm is easy. :-)  author
maintenance duties are to twiddle a published control file.
                                           
when authors aggregate (here's the political part), the path to that
aggregation's root module is taken to be the reversed path to the host
where the aggregation's control file is published.  see java.

for example:

  (define control-file-alist
    '((trigger . "http://www.glug.org/blah/blah/blah";) ...))

  (gumm-agg-root (assq-ref control-file-alist 'trigger))
     => (gumm org glug www)

thus, top-level gumm hiearchy is as follows:

  (gumm --install)      ; loading this module makes the "gumm"
                        ; prefix for future modules unnecessary
  (gumm personal)
  (gumm org)
  (gumm edu)
  (gumm com)            ; etc

this approach is simple if somewhat unsightly.  previously proposed
hierarchies fit into this one w/ little difficulty.

thi