improvements on searches:
- fix #33 (closed) concerning Metaplace autogeom when no place is associated
- generalize use of axiosjs for API requests (consistent with future developments with vuejs) and add the opportunity to cancel current request before starting new request (useful for search pages).
- bbox requests now available for metaplaces
- some map improvements (collapsable legend, control organization).
- datatables and leaflet are now populated with common a common axios request.