Don't copy vardecl items to output model that are already there.  Fixes #44.
Don't copy vardecl items to output model that are already there.  Fixes #44.

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