Added missing ncludes.
Added missing ncludes.

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