Allow Mapping of Default Success Events

It would be really helpful if you could map the default success events to custom events.  When you have to submit things like revenue and units via transaction ids, you can't use the default events and instead have to use custom events.  This makes it extremely difficult in many cases to use different tools due to the "hard-coding" of these events into different tools.  

It would be nice if we could just point the revenue event to a custom event in these situations.  

Even better would be for you to fix the bigger issue of not allowing us to use the default events with Transaction Ids.