There is no need to compile our DLLs as shared libraries since we are
managing symbols exports and imports through spec files.
On my system, this reduces the configure-time by a factor of two.
- Remove a non-recurring job from the job list after starting it.
- Remove a recurring job from the start list, calculate its next start time and insert it again.
- Calculate the timeout for the next job.
Use WaitForMultipleObjects in the mail scheduler loop:
- Use events to signal service stop and job update events to the main loop.
- Use the timeout timer to start the next job.
