Additional codes for GeoNames search
As noticed by Victoria some ancient places like ruins can't be found in the GeoNames search e.g. https://www.geonames.org/2468221/henchir-el-kasba.html
Since this will be quite useful for historical and archaeological projects we will add this class ("S spot, building, farm" see http://www.geonames.org/export/codes.html) to the OpenAtlas GeoNames search.
In case the results will get to confusing we will think about an advanced GeoNames search that the users can decide in which classes to search.