Use Node's EventEmitter semantics

[romgrk]

Bindings should integrate smoothly with target language, therefore:

EventEmitter#on <--> GObject#connect

Maybe even inherit from EventEmitter?

[romgrk]

GObject#on and GObject#off implemented in 90a390d. Both are implemented in javascript, using the native connect and disconnect behavior (which return signal's handle_id).

• Pass tests/object__events.js (.off is currently not working)
• Add documentation

[romgrk]

e060cc5

[benwaffle]

Should every GObject be an EventEmitter?

[romgrk]

Well the GObject framework is made so that every instance has event-listening capabilities, and it's recommended that GIR bindings integrate idiomatically with the language that's being binded, so it makes sense to have the same semantics as EventEmitter (on, off, and once).
However, those need to be implemented in terms of the native g_signal_connect_closure/g_signal_handler_disconnect (binded to .connect()/.disconnect()), so it's not really possible to just extend the EventEmitter class, unless we do something like this:

EventEmitter -> DerivedEventEmitter (implementing custom on/off/...) -> GObject

And it would also require getting an instance of the javascript EventEmitter's FunctionTemplate in C++ , which I'm not sure exactly how to do.