In my initial testing, I apparently missed that the Xbox One S wireless
controller has a different GUID than a regular Xbox One wireless
controller when used with the Xbox wireless dongle for Windows.
Also, add the GUID for the Xbox One Elite wireless controller, which
also has a different GUID than the regular Xbox One wireless when
used in wireless mode.
Querying the device list and checking whether IG_ is in the name does
not work on Windows 10 Anniversary Update (1607).
To work around that, we add the GUIDs for all Xbox One controllers.
This should fix the problem for the most common XInput devices for now.
Presumably, Microsoft will fix this later on. But for now, this will do.
The good thing about doing it this way is that it isn't a workaround per
se -- it's an optimization that already exists in the code.
Fixesmumble-voip/mumble#2483
This adds a dependency on a small library, XInputCheck, which is
a function abstracted away from SDL. All it does is check whether
a given DirectInput guidProduct is an XInput device.
