* orders: Fix manager not processing immediately
This ensures that orders are processed as soon as orderManager claims to have started.
Specifically this will fix an eager call to CancelAllOrders not finding
anything until after the first Interval run.
* orders: Fix reset timer call
This fix is small niggle.
The existing code was more complicated than it needed to be, whilst also
ignoring the return of timer.Reset and the conditional need to drain the
channel. It's unlikely but possible during transient resource
starvation.
* OrderManager: Simplify startup process
This simplifies the sequence and Adds to the wg first.
We won't bail from the run() during any type of processOrders, and
that's something we can fix later
466327cdaa