Content types

graceful currently talks only JSON. If you want to support other content-types then the only way is to override BaseResource.make_body(), BaseResource.require_representation() and optionally BaseResource.on_options() etc. methods. Suggested way would be do create a class mixin that can be added to every of your resources but ideally it would be great if someone contributed code that adds reasonable content negotiation and pluggable content-type serialization.