what about multiple events on the same spot?

[radekstepan]

Currently we are darkening the circles as per:

https://github.com/radekstepan/deadmonton/blob/master/src/views/canvas.coffee#L23

But perhaps this should be more prominent. For example by increasing the radius of the generated mega-circle.

We could do this quite efficiently by merging events in the source to the same point if they are close by (but at some point we will end up with one massive circle...) and then check if a different point is on our spot when placing it on the canvas.