Sign, Encrypt responses

[tmackenzie]

Given a request
When its handled by a RestResource
And the request header, Accept: application/jwt
Then return a signed jwt
And the set the response header, Content-Type: application/jwt

Given a request
When its handled by a RestResource
And the request header, Accept: application/jwe
Then return an encrypted jwt
And the set the response header, Content-Type: application/jwe