Add a papszSiblingFiles argument to GDALOpenEx()
GDALDriver: allow pfnIdentify to return -1 if Identify() is not able to determine if the file is recognized or not
Fix GeoJSON opening from http:// ressources
Make HTTP driver also work with vector drivers
Implement Identify() for CSV, DGN, DXF, GeoJSON, GML, KML, LIBKML, MapInfo File, NAS, OpenFileGDB, OSM, S57, Shape, SQLite and VRT