FEATURE/MINOR: server, bind: add allow-0rtt option

BUG/MINOR: validation: ease regex validations

Ease regex validation on backend_switching_rule to allow using
variables for backend name. Also remove regex check for cookie in
backend and defaults to allow adding extra cookie parameters.

MEDIUM: Add info endpoint

MINOR: backend: added hash-type option

MINOR: bind: add alpn option to binds

MAJOR: Cleanup sections options

BUG/MINOR: Remove bogus example from endpoint model

DOC: Fix typo