Logs that got sent sparsely or burstily would get buffered for long
periods of time since the logic to flush them only does so on the next
log write. In the worst case, a subsequent log write could never happen
and cause a log entry to be indefinitely buffered.
This fix introduces a recurring event/timer to simply flush all pending
logs at frequency of Broker::log_batch_interval.
It may generally be better for our default use-case, as workers may
save a few percent cpu utilization as this policy does not have to
use any polling like the stealing policy does.
This also helps avoid a potential issue with the implementation of
spinlocks used in the work-stealing policy in current CAF versions,
where there's some conditions where lock contention causes a thread
to spin for long periods without relinquishing the cpu to others.
For backward compatibility when reading values, we first check
the ZEEK-prefixed value, and if not set, then check the corresponding
BRO-prefixed value.
* All "Broxygen" usages have been replaced in
code, documentation, filenames, etc.
* Sphinx roles/directives like ":bro:see" are now ":zeek:see"
* The "--broxygen" command-line option is now "--zeexygen"
