With permission from the main authors [1], most of the code has been
relicensed under the MIT license.
SPDX license identifiers are used so that the license headers in source
code files aren't too large.
Add CONTRIBUTORS.rst file.
[1] https://github.com/rednex/rgbds/issues/128
Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>
Not all occurrences have been replaced, in some cases they have been
left as they were before (like in rgbgfx and when they are in the
interface of a C standard library function).
Signed-off-by: Antonio Niño Díaz <antonio_nd@outlook.com>
