Support "application/vnd.error+json" media type for new Extension/Error extention

 * Add `Extension/Error` framework extension for resource error handling
 * Support `application/vnd.error+json` media type as default `ErrorInterface` implementation.

see more about `vnd.error`
https://github.com/blongden/vnd.error

![2014-12-21 14 32 28](https://cloud.githubusercontent.com/assets/529021/5517275/3e01d602-891e-11e4-8b67-25bbd007b0ac.png)