- renamed client property `MACOS_WINDOW_BUTTON_STYLE` to `MACOS_WINDOW_BUTTONS_SPACING`
- no longer allow value `true` for that client property
- enable using `MACOS_WINDOW_BUTTONS_SPACING` without `apple.awt.fullWindowContent`
- remove client property `FULL_WINDOW_CONTENT_BUTTONS_BOUNDS` when `apple.awt.fullWindowContent` is set to false or null
- added placeholder options `zeroInFullScreen`, `leftToRight` and `rightToLeft`
- hide close/min/max buttons during the transition from full-screen to non-full-screen to avoid that they "jump" when the nsToolbar is made visible
- fixed: full-screen listeners where added multiple times
- updated macOS native libraries
- added `FlatMacOSTest`
- added title bar buttons placeholder
- added client property to root pane that contains title bar buttons bounds
- undone toolbar extensions from commit ea2447dcb7
- removed `FlatNativeMacLibrary.getWindowPtr()` because it is too dangerous to use `windowPtr` (which is `NSWindow*`) in Java (using invalid window pointer would crash app)
- made `getNSWindow()` 20x faster
- catch exceptions in `getNSWindow()`
- digitally signed dylibs