Voting methods for ranked, rated and approval ballots: the D21 (with
and without minus votes), first-past-the-post, two-round runoff, instant
runoff, the Borda count, approval voting, majority judgement and the
Condorcet method.
Automatic detection of ballot input type (ranking, cardinal
utilities, approvals and scores), configurable tie-breaking and tidy
summaries of the results.
Ballot generators for simulation: gen_ranks(),
gen_utilities() and gen_approvals().