Utility problem with setWatch

I see the reasoning, but if I understand right the issue here is it's not backwards compatible - all current modules (and users!) that have code that relies on the behaviour for rising and falling events will find that it stops working in a very non-obvious way, with no warnings or errors.

Surely the situation could just be improved by just changing the documentation, so it explicitly mentions the behaviour rather than just having the single sentance. Perhaps an optional argument could disable the behaviour, but if we're doing that it's probably better all around to just add the lastEventTime variable.

Anyone else want to chip in here?