Clutter 1.16 Beta 1 Updates the Wayland Backend

Clutter 1.16 Beta 1 updates the Wayland backend, in order to allow developers to use the brand-new 1.2 behavior and API, as well as to improve the coverage of windowing system features. Moreover, this release allows usage of ClutterContent on a ClutterStage, fixes device and event handling when using evdev, and drops support for XInput 1.x. It also brings fixes for the Windows backend, by updating the build script with the required dependencies.