* iface/dve2/dve2.cc (dve2_kripke::dve2_kripke): Fill
a format_filter_ array with boolean indicating whether each
variable should be printed. Ignore variable with only one
possible value.
(dve2_kripke::~dve2_kripke): Destroy it.
(dve2_kripke::format_state): Use it.
* iface/dve2/finite.test: Adjust.
* iface/dve2/dve2.cc (dve2_compressed_state): New class.
(callback_context): Deal with general state*s, not dve2_state*s.
(transition_callback_compress): New function.
(dve2_kripke): Take a compress option.
(get_init_state, compute_state_condition, succ_iter,
format_state, state_condition): Handle compressed states.
(get_vars, compute_state_condition_aux): New helper methods.
* iface/dve2/dve2.hh (load_dve2): Add a compress option.
* iface/dve2/dve2check.cc: Add a -z option.
* iface/dve2/finite.test, iface/dve2/dve2check.test: Add more
tests.
* iface/dve2/dve2.hh (load_dve2): Take a "dead" argument.
* iface/dve2/dve2.cc (callback_context): Add a destructor
to simplify...
(dve2_succ_iterator::~dve2_succ_iterator) ... this one.
(convert_aps): Skip the dead proposition.
(dve2_kripke::dve2_kripke): Take a dead argument, and
setup alive_prop and dead_prop.
(compute_state_condition, get_succ): Use a cache for the
conditions and successor of the last state, to share
some work between these two function. Add loops on dead
states.
(load_dve2): Pass dead to dve2_kripke and convert_aps.
* iface/dve2/dve2check.cc: Add a -dDEAD option.
* iface/dve2/finite.test, iface/dve2/finite.dve: New file.
* iface/dve2/Makefile.am: Declare them.
