3.0.0

A bunch of things that have bugged me
 * Update everything to rojoma-json 3 / simple-arm 2
 * Requests now get a ResourceScope attached to prevent IoC hell when streaming responses
 * The logging MDC is automatically cleared around each request
 * Rework charset handling for text data everywhere.  It is now more flexible and harder to get wrong.
 * JSON responses have a convenience response builder for anything with an associated JsonEncode
 * There is a convenient class (HttpRequest) to hang app-specific request data off of.
 * Allow hooking into Jetty's error handling for custom error page formatting

...but it'll have to come back for the next version, referring to 3.0.0.  I'll have to remember to do that tomorrow.