Memory leak: event listeners aren't removed (?)

[johanrd]

1. Go back and forth to a route with an element using the menu modifier, and take a heap snapshot between each time.
2. See that for every time, a new instance of Menu and MenuNavgation is retained (accumulating) in memory

Most probable cause seems to be that added event listeners in control aren't removed on component teardown.

[gossi]

Good catch. I was hoping to remove all references so JS GC can do its job. Apparently it's not the case.

Thanks for doing the investigation 👍

[gossi]

I had some dispose functionality already lying around. I did a quite cheap implementation in #269 - I didn't profile though. It is more to get it chained up, though it may have an effect already.

Released in 0.1.0