Initialise payload field in VarDecls
Initialise payload field in VarDecls

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