These were used in old experiments, but have not turned useful in
practice.  Not worth keeping and maintaining.

* src/tgbaalgos/cutscc.cc, src/tgbaalgos/cutscc.hh: Delete.
* bench/scc-stats/, bench/split-product/: Delete.
* configure.ac, src/tgbaalgos/Makefile.am, README, bench/Makefile.am:
Adjust.