- [API] Rename "0-RTT" to "session resumption." In IETF QUIC, "0-RTT" always refers to early data, meaning a request that the server can reply to in the very first return flight. A more appropriate name for what we support on the client site is "session resumption," which is standard TLS terminology. Later, when we add support for 0-RTT (early data), we can use the 0-RTT terminology again, this time in proper context. - [BUGFIX] Do not set certificate callback if ea_lookup_cert is NULL. - [BUGFIX] Make connection tickable when it's marked as closed. - [BUGFIX] Fail certificate lookup if SNI is not present in HTTP mode. - Several documentation fixes and improvements. - Minor code cleanup.