Code cleanups in panels/common
Since input helpers do not need synchronization with g-s-d anymore, and since we could use a single backend of GsdDeviceManager instead of 2, this code can be cleaned up quite a bit.
Since input helpers do not need synchronization with g-s-d anymore, and since we could use a single backend of GsdDeviceManager instead of 2, this code can be cleaned up quite a bit.