rename size() to qtail() and introduce shortcuts
ensure tactic goals are not updated if they are in inconsistent state (because indices could be invalidated)
- add sat.smt option to enable the new incremental core (it is not ready for mainstream consumption as cloning and other features are not implemented and it hasn't been tested in any detail yet).
- move "name" into attribute on simplifier so it can be reused for diagnostics by the seq-simplifier.
other updates:
- change signature of advance_qhead to simplify call sites
- have model reconstruction replay work on a tail of dependent_expr state, while adding formulas to the tail.
inc_sat_solver uses bit-blaster, card2bv and max_bv_sharing.
By turning these into simplifiers it will be possible to remove
dependencies on tactics and goals in inc_sat_simplifier and instead use a modular and general incremental pre-processing infrastructure.
