Fix sleeping collision end event

[liabru]

Fix for sleeping collision end event as discussed in #1077.

Branch includes an alpha build ready for testing and review of anybody affected looking to try out this fix and help confirm it works.

[nartallax]

Works for me. Thanks!

Here's my minimal example. This may be not typical case of this bug, but this fix still did it for me.

(and also I don't have a big complex app to test this build on, so my testing is not very extensive)