macOS: custom traffic light position

[tonsky]

I think what Electron does is the most reliable way. IIRC it puts default buttons into its own View and then positions that container in main window. Positioning individual buttons won’t work. Another crucial (and very obscure) detail is that container that contains those buttons must respond to some selectors, otherwise it will behave weird. See https://stackoverflow.com/a/30417372/142655