This adds a new joystick backend, implemented on top of HID and without
any host dependencies. This will be progressively implementated, and
it's not going to be usable until at least a few more patches.

Because of that, and because it may also introduce regressions compared
to the existing backends, it is disabled by default and is optionally
enabled using the following global registry key:

  [HKCU\\Software\\Wine\\DirectInput\\Joysticks]
  "HID"="enabled"

Or using the corresponding AppDefaults registry key:

  [HKCU\\Software\\Wine\\AppDefaults\\<app.exe>\\DirectInput\\Joysticks]
  "HID"="enabled"

This setting will be removed later, when it becomes usable enough, to
use the individual device disable mechanism available in joy.cpl.
Signed-off-by: Rémi Bernon <rbernon@codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard@winehq.org>