Missing resources management

[Azbesciak]

Hi, I noticed (because of the problems I have) that listeners on draw events are not released with ngOnDestroy. The question is - why? Is it because of performance reasons or does it seem to be unnecessary?

My scenario is that I have a single draw control for multiple groups of layers, one group active to edit/add at the time. I need to swich between them, and I came to an idea to reuse the single control (multiple events emitted, for each - I think it is better to have a single place where it is managed).
But the problem is with those events, all the time new one is added, whereas the directive is still the same.

[reblace]

I can try to fix this in a minor release. I agree we should be cleaning those up on destroy.