Its important to stop the threads before we let
the other smart point objects naturally deconstruct
to avoid thread-based race conditions.
The attempt to deconstruct the tree and soft time ctrl
had a bug because the tree had references in subtrees
within the dboard manager class.
Rather than continue to fix this method and
deconstruct the tree to free up soft time ctrl,
it seems simpler to just stop the thread in soft time ctrl,
and then let it naturally deconstruct later by ref count.
Moved the underflow/overflow polling into a thread and out of the fast-path.
Added an inline and async message queue into soft time control.
Error and status messages are actually generated now and enqueued.
Passes the async message test...
