A few functions and Gameframe integration

• Added winwin_keyboard_clear, winwin_mouse_clear, winwin_io_clear
• Added winwin_is_minimized, winwin_is_maximized, winwin_minimize, winwin_maximize
• Added winwin_set_shadow, winwin_get_shadow (for border-less windows)
• Fixed some sizing oddities in winwin_set_size and winwin_set_rectangle

If you’re also using Gameframe, checkout Gameframe x Windows’ windows integration!