[GeoJSON] RFC-2

[Martin Daly]

> Any other suggestions?  In particular, if anybody has any 
> other suggestions for crs conventions, it would be good to hear them.

OGC URNs (http://portal.opengeospatial.org/files/?artifact_id=16339) and
OGC WKT (http://portal.opengeospatial.org/files/?artifact_id=18241)
might be worth referencing.

Another madcap idea would be to devise a GeoJSON CRS object itself,
following the GeoJSON Object conventions, e.g. 

"crs": {
  "type": "Geographic",
  "properties": {
    "name": "Latitude/Longitude WGS_1984",
    "datum": {
      "type": "Geodetic",
      "properties": {
        "name": "WGS_1984",
        "spheroid": {
            "type": "struggling to think of a good type here",
            "properties": {
              "name": "WGS 84",
              "semi_major_axis": 6378137.0,
              "inverse_flattening": 298.257223562997
            }
          }
        }
      },
      "prime_meridian": {
        "type": "struggling here too",
        "properties": {
          "name": "Greenwich",
          "longitude": 0.0
        }
      },
      "units": {
        "type": "Angular",
        "properties": {
          "name": "Degrees",
          "to_radians": 0.0174532925199433
        }
      }
    }    
  }
}

For the record, the matching OGC WKT is:

GEOGCS["Latitude/Longitude WGS_1984",DATUM["WGS_1984",SPHEROID["WGS
84",6378137,298.257223562997]],PRIMEM["Greenwich",0],UNIT["degrees",0.01
74532925199433]]

M