* Assign boolean variables only to long-lived constraints, and deduplicate constraints when they are created
* scoped_signed_constraint
* update other classes
* fix
* Don't use scoped_ptr<constraint> with dedup()
* Rename solver_scope for fixplex tests
(otherwise the wrong constructor is called for polysat's solver_scope)
* Update conflict_core
* simplify
* Be clearer about constraint_literal lifetime
* remove old comment
* Remove status (positive/negative) from constraint
* Use constraint_literal in the solver
* Fix build (constraint -> get_constraint)
* Refactor: remove sign and dep from constraint
* fix some bugs
* improve log messages
* Add missing premises to lemma
* Rename getter in an attempt to fix linux build