This C extension implements a priority-queue object using a fibonacci heap as the underlying data structure. This data structure supports the following operations with the given amortized time-complexity: - insert: O(1) - find-min: O(1) - extract-min: O(lg N) - decrease-key: O(1) - increase-key: O(lg N) (== delete, insert) - delete: O(lg N) (== decrease-key, extract-min)