Add headers for the title and game-over screens, contributed by Gab1975.

* Contains optimised PNG images.
* Contains the required support code.
* "Welcome to HOCOSLAMFY" and "GAME OVER" are replaced with the header images.
* Update and clarify the copyright file, now that not all graphical artwork is by the same person.
* The copyright file is now in the release and can be found by extracting it.
Remove disused file data/column.png.