Allow multiple should_enqueue_log_record hooks to be registered,
and take advantage of that inside the shaping helper.
`shaper.should_enqueue_log_record` no longer needs to be explicitly
plumbed from the config, but we allow calling it still for compatibility
reasons.
We will remove that compatibility after the next stable release.
Using the init_with_tsa.lua policy for kumod, together with
tsa_init.lua as the policy for tsa-daemon, logs from kumod
are now sent to tsa-daemon.
It doesn't do anything with them yet.
Wez Furlong
Mike Hillyer