Added support for getting the real controller info, as well as the function SDL_GameControllerGetSteamHandle() to get the Steam Input API handle, from the virtual gamepads provided by Steam.
Also added an event SDL_CONTROLLERSTEAMHANDLEUPDATED which is triggered when a controller's API handle changes, e.g. the controllers were reassigned slots in the Steam UI.
(cherry picked from commit c981a597dc7c69e7532796b3a206071807479d35)
- SDL_JoystickGUID -> SDL_GUID (though we retain a type alias)
- Operations for GUID <-> String ops are now in
src/SDL_guid.c and include/SDL_guid.h
- The corresponding Joystick operations delegate to SDL_guid.c
- Added test/testguid.c
This prevents conflicts with hidapi linked with applications, as well as allowing applications to make use of HIDAPI on Android and other platforms that might not normally have an implementation available.
