Rewrite owner-drawn close button handling to actually work
Rewrite owner-drawn close button handling to actually work

Closes GH-9

jeffkowalski/mintrayr,nmaier/mintrayr,jeffkowalski/mintrayr,jeffkowalski/mintrayr,nmaier/mintrayr,nmaier/mintrayr,nmaier/mintrayr,jeffkowalski/mintrayr