No way to unbind event handler

[CliffCawley]

Just discovered an issue where the event was still being fired on an already destroyed instance.

You don't provide a way to unbind the event handler that's setup in the InitTimer call.

It would be good if you provided a DestroyTimer() call that stopped the timer and unbound the event handler.

I can make the relevant changes and send a PR if required :)

[ufuf]

I would appreciate if you can send a PR.
Best,
Ufuk