InputHandler: Temporary disable input handler

fix #754

At this time I have no good idea for fix on this, but because this
causes that giu is useless, I've decided to disable very specific part of the framework that is not essential

MasterWindow.go

@@ -382,13 +382,15 @@ func (w *MasterWindow) SetShouldClose(v bool) {
 func (w *MasterWindow) SetInputHandler(handler InputHandler) {
 	Context.InputHandler = handler
 
-	w.backend.SetKeyCallback(func(key, scanCode, action, modifier int) {
-		k, m, a := keyFromGLFWKey(imgui.GLFWKey(key)), Modifier(modifier), Action(action)
-		handler.Handle(k, m, a)
-		if w.additionalInputCallback != nil {
-			w.additionalInputCallback(k, m, a)
-		}
-	})
+	/*
+		w.backend.SetKeyCallback(func(key, scanCode, action, modifier int) {
+			k, m, a := keyFromGLFWKey(imgui.GLFWKey(key)), Modifier(modifier), Action(action)
+			handler.Handle(k, m, a)
+			if w.additionalInputCallback != nil {
+				w.additionalInputCallback(k, m, a)
+			}
+		})
+	*/
 }
 
 // SetAdditionalInputHandlerCallback allows to set an input callback to handle more events (not only these from giu.inputHandler).