* src/ltlvisit/simplify.cc: Integrate the tau03
containment rules.
* src/ltlvisit/simplify.hh: Add options to select simplifications.
* src/ltlvisit/reduce.cc (reduce): Do not call reduce_tau03().
* src/ltlvisit/contain.cc (reduce_tau03_visitor): Remove.
(reduce_tau03): Implement it using ltl_simplifier.