The primary motivation behind this change was documentation of
links. Developers (including myself---it's been a while) misinterpreted
then as references to existing groups, not arbitrary names.
* doc/program.texi (Defining Groups): New section.
(Group Styles): Reference to new section.
What a cluster.
This was a lot of work to work around existing, bad APIs; there is no
time to refactor at the moment; this already took much longer than
expected.
* assert.texi, bucket.texi, client.texi, pred.texi, program.texi,
validation.texi: New files.
* design.texi: Extract text into above.
* liza.texi: Add @menu references and @include each new file.