RFC 7515 needs to have base64url encoded strings

[mickenordin]

3.2. JWS JSON Serialization Overview

In the JWS JSON Serialization, one or both of the JWS Protected
Header and JWS Unprotected Header MUST be present. In this case, the
members of the JOSE Header are the union of the members of the JWS
Protected Header and the JWS Unprotected Header values that are
present.

In the JWS JSON Serialization, a JWS is represented as a JSON object
containing some or all of these four members:

o "protected", with the value BASE64URL(UTF8(JWS Protected Header))
o "header", with the value JWS Unprotected Header
o "payload", with the value BASE64URL(JWS Payload)
o "signature", with the value BASE64URL(JWS Signature)

The three base64url-encoded result strings and the JWS Unprotected
Header value are represented as members within a JSON object. The
inclusion of some of these values is OPTIONAL. The JWS JSON
Serialization can also represent multiple signature and/or MAC
values, rather than just one. See Section 7.2 for more information
about the JWS JSON Serialization.

[glpatcern]

Good catch Micke! Yet I would not merge this right away as with the Distributed Discovery it's largely superseded. Let's discuss later today.