It was a mistake to try to overload And/Or LTL operator for these when
trivial simplification are performed.  The reason is so simple it is
embarassing: And(f,1)=f is a trivial identity that should not be
applied with AndRat.  E.g. AndRat(a;b, 1) is equal to 0, not a;b.

* src/ltlast/multop.hh, src/ltlast/multop.cc: Add the AndRat and OrRat
operators.
* src/ltlparse/ltlparse.yy: Build them.
* src/ltlvisit/mark.cc, src/ltlvisit/simplify.cc,
src/ltlvisit/tostring.cc, src/tgba/formula2bdd.cc,
src/tgbaalgos/eltl2tgba_lacim.cc, src/tgbaalgos/ltl2taa.cc,
src/tgbaalgos/ltl2tgba_fm.cc, src/tgbaalgos/ltl2tgba_lacim.cc:
Adjust all switches.