Remove couldBeClause from WeightConstraint.
Implement at-most-one (pairwise up to 8 literals, bimander otherwise).
Add bisequential.
Merge branch 'competition' of https://github.com/alviano/wasp into competition
Merge branch 'competition' of https://github.com/alviano/wasp into competition
Disable atmostone rewriting.
Rename aggregateToClause to atLeastOne.