Open-WBO16 -- minor improvements for partial MaxSAT over the Open-WBO15 version

Papers:
- Miguel Neves, Ruben Martins, Mikolás Janota, Inês Lynce, Vasco M. Manquinho:
  Exploiting Resolution-Based Representations for MaxSAT Solving. SAT 2015: 272-286

- Ruben Martins, Saurabh Joshi, Vasco M. Manquinho, Inês Lynce:
  Incremental Cardinality Constraints for MaxSAT. CP 2014: 531-548

- Ruben Martins, Vasco M. Manquinho, Inês Lynce:
  Open-WBO: A Modular MaxSAT Solver. SAT 2014: 438-445