Added love.window.minimize (resolves issue #904).

src/modules/window/sdl/Window.cpp

@@ -601,6 +601,12 @@ love::image::ImageData *Window::getIcon()
 	return curMode.icon;
 }
 
+void Window::minimize()
+{
+	if (window != nullptr)
+		SDL_MinimizeWindow(window);
+}
+
 void Window::swapBuffers()
 {
 	SDL_GL_SwapWindow(window);

src/modules/window/sdl/Window.h

@@ -68,6 +68,8 @@ public:
 	bool setIcon(love::image::ImageData *imgd);
 	love::image::ImageData *getIcon();
 
+	void minimize();
+
 	void swapBuffers();
 
 	bool hasFocus() const;