Jormungandr: add error to places API

There was no error field for places and places_nearby apis
ptref: correction on filter for places nearby

There was a messed up in the filter for the places nearby API since the
proximity list does not return list sorted on the index
ptref: cleanup and translations
ptref: add unit tests
Merge pull request #363 from antoine-de/NAVITIAII-845

Navitiaii 845