GNUmakefile: drop obsolete --memlimit argument to sage -t.
mjo-hurwitz.tex: new file for Hurwitz algebras (quaternions and octonions).
GNUmakefile: change a non-POSIX "echo -n" to printf.
GNUmakefile: simplify recursive logic and eliminate a "pdflatex" call. In the recursive $(MAKE), the sub-$(MAKE) can succeed and then subsequently delete its "previous" file. When that returns control to the parent $(MAKE), the parent will try to diff the (now missing) "previous" file against the latest one, which of course fails. This leads to an extra build of the same, current, not-gonna-change PDF. A slight change in the logic both simplifies things and eliminates that extra rebuild. Thanks to Wojtek Kosior who pointed out the bug in an email.
GNUmakefile: use SOURCE_DATE_EPOCH=0 instead of "sed" to prevent rebuilds.
GNUmakefile: don't repeat BIBPATHS and MJOTEXPATHS in "make dist". The variables $BIBPATHS and $MJOTEXPATHS are already appended to $SRCS when needed, and $SRCS is handled by "make dist."
GNUmakefile: make check-chktex output errors.
GNUmakefile: ensure the indices are rebuilt when the document changes.
mjo-misc: rename to mjo-set.
GNUmakefile: remove inappropriate PYTHONPATH mangling. This isn't needed here; it was copy/pasted from one of my publication repositories where it is.
GNUmakefile: fix blank line handling in SageMath listings.
GNUmakefile: update a bug reference in a comment.
GNUmakefile: oops, fix the index generation again.
GNUmakefile: fix rebuild loop caused by idx file regeneration.
GNUmakefile: update the cleanup rules.
GNUmakefile: add some documentation for the INDICES variable.
Enable a bibliography by default.
Add index support.
GNUmakefile: tweak that last commit to use the DSTS instead of SRCS.
GNUmakefile: rebuild if a sage listing is modified.