* Extend search state by boolean literals
* Only resolve against positive equality
* mk_dep_ref
* Make clause non-owning
* scoped_clause
* Use scoped_clause
* minor
* scoped_ptr move assignment
* WIP: internal handling of disjunctive constraints
* leaf_value
* disjunctive constraints continued
* Fix bool_lit
* Actually add constraints to storage
* Some fixes
* more fixes
* constraint should have a bool_lit instead of a bool_var
* propagate(bool_lit)
* updates
* interface changes
* small fixes
* Make sat::dimacs_lit's constructor explicit
(otherwise, calling operator<< with sat::literal is ambiguous)
* Use sat::literal
* Print test name at the beginning
* Convention: constraint corresponds to the positive boolean literal
* Make constraint ownership more explicit
* clause stores literals
* Pop assign_eh
* Fix scoped_ptr_vector constructors, add detach()
* Need to copy the returned lemma
* Add test
* Basic inequality tests
* Return disjunctive lemma to caller
