Fix why3doc output so that documents are not implicitly ended.
Fix why3doc output so that documents are not implicitly ended.

jpdeplaix/why3,douglas-larocca/why3,ssaavedra/why3,jpdeplaix/why3,douglas-larocca/why3,ssaavedra/why3,ssaavedra/why3,jpdeplaix/why3,douglas-larocca/why3