* src/tgba/bddprint.cc, src/tgba/bddprint.hh: Add bdd_print_isop
that prints the bdd into a Irreductible Sum Of Product.
* src/tgbaalgos/dupexp.cc, src/tgbaalgos/dupexp.hh: Add a way to
know which states (in the input) is which (in the result).
* src/tgbaalgos/simulation.cc, src/tgbaalgos/simulation.hh: Add
the Don't Care Simulation and the Don't Care Iterated Simulation.
* src/tgbatest/ltl2tgba.cc, src/tgbatest/spotlbtt.test,
src/tgbatest/Makefile.am, src/tgbatest/sim.test: Test them.
* bench/ltl2tgba/algorithms, bench/ltl2tgba/README,
bench/ltl2tgba/algorithms: Add a way to bench the don't care
simulation.