Allow creating a window without depending on the whole GUI system? #157
Description
If DsrWindow inherits from a simpler type of window without the component system and the window_ methods in guiAPI are separated into its own API header, it should be possible to reduce dependencies for programs that do not need any GUI components, so that there is less code that can cause problems in the future. It would also make a cleaner start for anyone wanting to experiment with their own GUI systems from scratch. Pixel up-scaling should still exist in the simplest type of window, because it can be used for faster canvas uploads using native upscaling tricks in the future.