Add hint SDL_HINT_MOUSE_TOUCH_EVENTS for mouse events to generate touch events

controlling whether mouse events should generate synthetic touch events
By default SDL will *not* generate touch events for mouse events

include/SDL_hints.h

@@ -315,6 +315,18 @@ extern "C" {
  */
 #define SDL_HINT_TOUCH_MOUSE_EVENTS    "SDL_TOUCH_MOUSE_EVENTS"
 
+/**
+ *  \brief  A variable controlling whether mouse events should generate synthetic touch events
+ *
+ *  This variable can be set to the following values:
+ *    "0"       - Mouse events will not generate touch events
+ *    "1"       - Mouse events will generate touch events
+ *
+ *  By default SDL will *not* generate touch events for mouse events
+ */
+
+#define SDL_HINT_MOUSE_TOUCH_EVENTS    "SDL_MOUSE_TOUCH_EVENTS"
+
 /**
  *  \brief Minimize your SDL_Window if it loses key focus when in fullscreen mode. Defaults to true.
  *