s3 storage: set region even if not needed

add change log

fix docker workflow file

support for arm64 docker images

publish to docker hub

server: store tokens hashed with argon2

Auth tokens aren't stored as plaintext on the server but
are hashed with argon2. The salt is the creation time of the token.

Temporary tokens aren't hashed because they are short-lived (10 min max from creation till redemption).

https://github.com/P-H-C/phc-winner-argon2/blob/master/argon2-specs.pdf

server: redirect to how to on github

server: respond 401 for unknown tokens

fix forwarded headers

fix main class