First version with NTV and Table Schema format

• add Table Schema interface
• Table Schema type / format supported:
  • numerical: integer/default, boolean/default, number/default
  • json: object/default, array/default, string/default, string/uri, string/email
  • datation: datetime/default, date/default, time/default, yearmonth/default, year/default
  • location: geopint/array, geojson/default
• additional type / format supported (Table Schema extension):
  • numerical: number/floatxx, integer/intxx, integer/uintxx
  • json: string/file, object/null, object/object
  • datation: date/day, date/wday, date/yday, date/week, time/hour, time/minute, time/second
  • location: geojson/geometry, geojson/polygon, geojson/line
• correspondance between NTVtype and type/ format in ntv_table.ini