* src/tgbaalgos/word.cc, src/tgbaalgos/word.hh: New files.
* src/tgbaalgos/Makefile.am: Add them.
* src/tgbatest/ltlcrossce.test: New file.
* src/tgbatest/Makefile.am: Add it.
* src/bin/ltlcross.cc: Compute and display an accepted word
for nonempty cross-products.
* NEWS, doc/org/ltlcross.org: Document it.
