GeoJSON allows more than two values in coordinate-array (http://geojson.org/geojson-spec.html#positions).
Of course 2dsphere honours only the first two, but it should be allowed to add more (altitude, measure, etc).
-> should be considered in geoparser, see attachments
- is duplicated by
SERVER-21607 2dsphere index does not accept valid GEOJSON with 3 coordinates