device: Impose per-backend DeviceManager
The DeviceManager class should be abstract in Clutter, and implemented by each backend, as different backends will have different ways to detect, initialize and list devices; the X11 backend alone has *two* ways of dealing with devices. This commit makes DeviceManager an abstract class and delegates the device initialization and enumeration to per-backend sub-classes. The responsible for creating the device manager is, obviously, the backend singleton. The X11 and Win32 backends have been updated to the new layout; the Win32 backend has been updated blindly, so it might require additional testing.
Showing with 930 additions and 246 deletions