Make the windows work in fullscreen. The card window still stays fixed in place until we implement resizing.
Since Cocoa is too stupid to tell apart booleans and ints in some cases, make our ObjC/Hammer type conversion code force the issue by using CoreFoundation’s boolean singletons kCFBooleanTrue and kCFBooleanFalse instead, which we can identity-compare later.
Track Sparkle and UliKit HEAD, which gives us a few more fullscreen widgets on some windows.