Add array_union and array_intersect par builtins
Add array_union and array_intersect par builtins

nathanielbaxter/libminizinc,tias/libminizinc,jjdekker/libminizinc,nathanielbaxter/libminizinc,jjdekker/libminizinc,tias/libminizinc,jjdekker/libminizinc,jjdekker/libminizinc,nathanielbaxter/libminizinc,nathanielbaxter/libminizinc