geojson/draft-geojson — pull request #17 by sheppard (2014-01-08 18:55:17+00:00)
Title: how to use default crs

One more larger change. This might need a bit more discussion, or you may want to take a different approach. (So feel free to close / not merge for now.)

Basically the goal is to be more explicit about how to "specify" the default CRS, and in particular draw out the distinction between `crs: null` and no crs.