Updated the Ship class to change rum rate exactly like the Ports do now.  This code is duplicated, and probably should be in a base class or a component.
Changed all transaction events to use unsigned integers because that's what rum and gold is stored as now.
Yet another tweak that gets this working as it was intended.  Now ports and ships don't accumulate rum time when they're at the limit their rum rates are driving them to, but they DO accumulate rum time at all other times.