Refactor isc_job_run to not-make any allocations
Change the isc_job_run() to not-make any allocations. The caller must make sure that it allocates isc_job_t - usually as part of the argument passed to the callback.
For simple jobs, using isc_async_run() is advised as it allocates its own separate isc_job_t.
Use the new improved API to execute connect, read and send callbacks from netmgr in more straightforward manner, speeding up the networking.
Closes #3961 (closed)
Edited by Ondřej Surý