Unbinding window events when cancelling hide

[dominicbarnes]

Currently, the window events can be bound multiple times in some cases. If the hide is cancelled,
then show is called again (ie: mouseover/out fun times) the winEvents simply get bound again,
causing the previous handler to be forever bound (since unbind only gets the last one in the stack
apparently, probably needs to be addressed in component/events somehow)

This could probably be addressed more completely by using mouseenter/leave instead of mouseover/out,
but that is not addressed in this commit.

[Swatinem]

Reading the code, the difference between .events and .handleEvents is really confusing.

The .events case set up in cancelHideOnHover does not do a show, so you would completely unbind the events in that case.

[dominicbarnes]

Yeah, looks like if a user cancels the hide manually, that would remove the winEvents altogether.

The real trouble imo is that component/events is not aware of the fact that the same method is being bound repeatedly. (and once that happens, there is no way to unbind it)

[pirxpilot]

If we are concerned about not registering events more than once let's create winEvents (only if it does not exist) in show and then unbind all in remove and reset winEvents to null: should be safer than predicting all the possible sequences of registering and unregistering window events.