3.1.1
    * No changes.

3.1.0
    * DataSource's sendRequest() argument signature has changed in a
      non-backward-compatible way. It now accepts a single object containing
      the properties "request", "callback", and "cfg".
    * DataSource.Get bug fixed where it was trying to delete the proxy callback
      in the wrong location during cleanup.
    * Changed from array of proxy callbacks to object with guid keys to support
      services that don't properly handle array indexes in the callback
      parameter (Twitter)
    * Code reorganized (API and functionality unaffected)

3.0.0
    * DataSource.IO now passes request value to IO.
    * DataSource.Function now catches exception and fires error event.

3.0.0 beta 1
    * Initial release.
