Adopt draft-ietf-httpbis-message-signatures

[georgkrause]

The references are updated and the implemented standard is again superseded by httpbis.

You can track the current status of the draft here: https://datatracker.ietf.org/doc/draft-ietf-httpbis-message-signatures/

The Funkwhale Collective might have funding available to make this lib comply to the draft again, please get in touch asap if you are interested

[petterreinholdtsen]

I guess this project is abandoned. I would love to see an update with httpbis-message-signatures support.