Backport Emacs HEAD's fullscreen mode option #23729
This makes it possible to bypass OS X's fullscreen mode. The changes
This resolves the issues folks had (e.g. #15448) with the now exclusive use of OS X's fullscreen and makes it possible to get behavior similar to the behavior back when homebrew included a fullscreen patch.
And again, this is stuff coming down the pipe from upstream anyway. This just pulls in the current configurable behavior from their repo. With this patch applied you can switch to the old fullscreen behavior by setting: