* Force live results store once holdings changes settle

Monitor the securities holdings quantity changes in the live trading
result handler and force a store of the full results once the changes
have settled for a configurable period (holdings-changed-store-delay,
defaults to 10 seconds), so stored results reflect fills quickly
instead of waiting for the next scheduled store.

* Encapsulate holdings change monitoring in a private nested class

* Monitor order events instead of holdings quantity changes

The holdings change monitor now subscribes to the transaction handler's
NewOrderEvent and tracks fills, instead of wiring into every security
holding QuantityChanged event, which required monitoring the securities
collection changes as well.

* Revert local test changes to Launcher config

* Remove snapshot step from holdings change monitor

* Stamp holdings changes with the order event time