* updates related to issue #5140
* updated/simplified some cases
* fixing feedback comments
* fixed comments and added missing case for get_re_head_tail_reversed
* two bug fixes and some other code improvements
* Add macro to disable linear solver for development
* Move new_* and add_* to header
* Add ref_vector_core::push_back(ref<T>&&)
* Attempt to simplify lifetime handling
* Make operator bool() explicit
* clause improvements
* display boolean assignment
* clause::resolve
* bug fixes
* more fixes
* final case of backtrack
* 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
* Rename to neg_cond
* Add some logging utilities
* Implement case of forbidden interval covering the whole domain
* Implement diseq_narrow
* Do not activate constraint if we are in a conflict state
* comments
* Assert that lemma isn't undefined
* Update revert_decision to work in the case where narrowing causes propagation
* Fix case of non-disjunctive lemma from forbidden intervals
* Conflict should not leak outside user scope
* Add guard to decide(), some notes
* Add test case
* Add constraints to watchlist of unassigned variable during propagation
* Move common propagation functionality into base class
* Combine eq/diseq narrow
* Compute forbidden interval for equality constraints by considering them as p <=u 0 (or p >u 0 for disequalities)
* 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
* Fix XOR over BDDs
* Add operator<< for find_int_t
* Add equality assertion macro that prints expression values on failure
* Adapt contains_int and find_int to take externally-defined bits
* Add more operations on BDD vectors
* Remove old functions
* Additional bddv functions
* Rename some things
* Make bddv a class and add operators
* Fix find_num/contains_num calls
* Add a few helper methods for encoding sets of integers as BDDs
* Use BDD functions in solver
* Add bdd::find_int
* Use bdd::find_int in solver
* Add narrowing for linear equality constraints
* Simplify code for linear propagation
* Add test for later
* Narrowing can only handle linear constraints with a single variable
* Need to push_cjust
