openlayers/ol3 — pull request #927 by tschaub (2013-08-27 16:56:46+00:00)
Title: Accept null crs in GeoJSON

The [spec](http://geojson.org/geojson-spec.html#coordinate-reference-system-objects) allows a GeoJSON object to have no `crs` member. If it does have a `crs` memeber, it must be `null` or an object.