Picat: added coins_of_the_realm.pi
ASP: Ported Gringo 3 encodings to Gringo 4 (ASP-2). Added coins_of_the_realm.lp4
MiniZinc: Fixed calculs_d_enfer.mzn. Added farmer_and_cows.mzn farmer_and_cows_mip.mzn odd_even_sequences.mzn sum_of_next_natural_numbers.mzn