Remove duplicate unused code.

src/modules/window/Window.h

@@ -151,9 +151,6 @@ public:
 
 	virtual bool isVisible() const = 0;
 
-	virtual void setMouseVisible(bool visible) = 0;
-	virtual bool getMouseVisible() const = 0;
-
 	virtual void setMouseGrab(bool grab) = 0;
 	virtual bool isMouseGrabbed() const = 0;
 

src/modules/window/sdl/Window.cpp

@@ -886,16 +886,6 @@ bool Window::isVisible() const
 	return window && (SDL_GetWindowFlags(window) & SDL_WINDOW_SHOWN) != 0;
 }
 
-void Window::setMouseVisible(bool visible)
-{
-	SDL_ShowCursor(visible ? SDL_ENABLE : SDL_DISABLE);
-}
-
-bool Window::getMouseVisible() const
-{
-	return (SDL_ShowCursor(SDL_QUERY) == SDL_ENABLE);
-}
-
 void Window::setMouseGrab(bool grab)
 {
 	mouseGrabbed = grab;

src/modules/window/sdl/Window.h

@@ -83,9 +83,6 @@ public:
 
 	bool isVisible() const;
 
-	void setMouseVisible(bool visible);
-	bool getMouseVisible() const;
-
 	void setMouseGrab(bool grab);
 	bool isMouseGrabbed() const;