Adds tests for the echo-loop fix (outgoing X-Tags header, inbound skip
on tagged events, genuine tags pass through) and extends the tag to the
out-of-process _standalone_send() path so cron / send_message deliveries
to a self-subscribed topic are also skipped. Maps both contributors in
release.py AUTHOR_MAP.
Co-authored-by: liuhao1024 <sunsky.lau@gmail.com>
8055d0f092