Initial API implemented for notifying applications that an ASYNC_JOB
has completed. Currently only s_server is using this. The Dummy Async
engine "cheats" in that it notifies that it has completed *before* it
pauses the job. A normal async engine would not do that.
Only the posix version of this has been implemented so far, so it will
probably fail to compile on Windows at the moment.
Reviewed-by: Rich Salz <rsalz@openssl.org>
Create a "null" async implementation for platforms that lack support. This
just does nothing when called and therefore performs synchronously.
Reviewed-by: Rich Salz <rsalz@openssl.org>
