Message queue: handler responses _must_ be of {:status <>} form
Add `redis-call` fn for raw Redis requests (suggestion by 'ToBeReplaced')
Modify `make-conn-pool` for common-use case: nil pool-opts now gives default pool

This previously gave a degenerate pool which is a pretty uncommon desire. The
`{}` conn idiom now gives more sensible behavior by default.

A degenerate pool can still be created by using `:none` for the pool opts.
Update TODOs
Protocol housekeeping: spare the poor !s
Initial commit
BREAKING: Unserialized bytes no longer wrapped in vec

This was a silly decision since array .length is O(1) anyway and
probably cheaper than the vector destructuring. Dropping the unnecessary
wrapping is more consistent and allows easier tooling (e.g. parsers).
Update README
Speed boost: avoid `apply` for protocol requests
Housekeeping
Message queue: Add worker :eoq-backoff-ms fn support
~WIP Tundra