Switch to Object.defineProperty (probably breaking change)

[PlasmaPower]

MDN states about __defineGetter__ and __defineSetter__:

This method should not be used since better alternatives exist.

In this case, the better alternative would be Object.defineProperty. However, using this probably be a breaking change since defineProperty cannot easily be used to add a setter to something with currently only a getter. Doing that would mean recreating the property, which isn't exactly a clean solution. In addition, a property can be set to be not configurable, which means that that wouldn't work. I'd prefer not to add code to recreate the property to node-delegate.

[tj]

-1, no point IMO, those two aren't going anywhere