Implemented CheckLatency and MaxLatency setting.

We have some time drift between our systems and our counterparty, and needed CheckLatency=False or the ability to adjust the MaxLatency. The default currently is hardcoded as CheckLatency=True and MaxLatency=120 (seconds).

I implemented both/ completed the implementation for both.
There is one more //FIXME added in DoPossDup that needs attention to complete this.