This is needed to handle cases where XInput is being emulated, such as when running via Steam with the Steam Controller active. Steam's shim does not send out WM_INPUT_DEVICE_CHANGE events.
The new implementation uses a message-only window to register raw input events.
XInput is still used when possible, but raw input is being used to handle device detection. (XInput is only enabled when an XInput device is plugged in, which also prevents us from having to load and poll the XInput library unnecessarily.)
For raw devices, the Windows HID parser library is used to parse the raw data. Unfortunately, the Windows 7.1 SDK does not ship hid.lib (which is in the WDK 7.1.0), so I am dynamically loading hid.dll to prevent pulling in a dependency on the WDK. (But perhaps we can ship hid.lib in the thirdparty libraries?)
Input devices other than XInput gamepads and the 3D mouse have not been tested very well yet. Adding keyboard and mouse support is still a TODO.
This also splits out the Windows implementation of InputDeviceManager into a separate subclass; it is intended that the other implementations will follow suit.
rdb