Ignore device events for device management
The CLUTTER_DEVICE_ADDED/REMOVED events shouldn't count as "user interaction". Also, avoid stack-allocated events. All easy-backport candidates from wip/carlosg/input-thread.
The CLUTTER_DEVICE_ADDED/REMOVED events shouldn't count as "user interaction". Also, avoid stack-allocated events. All easy-backport candidates from wip/carlosg/input-thread.