with GPLv3 boilerplate file and README.md says "GPLv3 or later";
- Milton comes with custom TTF font, without it GUI looks pretty bad,
so install it under ${DATADIR} and set the font path in the program;
- Similar to WIN32 code, set window icon in the platform_setup_cursor()
function using the IMG_Load() from SDL2 ``image'' package. While it
can load Windows ICO files directly, for files with multiple images,
the first one found with the highest color count is chosen, which in
our case is 16x16x32 (the smallest). Tentatively extract all icons
as PNG files, install them all, and use 256x256 icon by default.
c4a01e479e