Reuse compatibility

[Libor Polčák]

Hello,

master branch is now compatible with reuse 
https://reuse.readthedocs.io/en/stable/readme.html

"Congratulations! Your project is compliant with version 3.0 of the REUSE 
Specification :-)"

I changed a little bit the usual file header to also include Doxygen tags. So 
author, copyright, and license information should be propagated to the Doxygen, 
see https://www.fit.vutbr.cz/~ipolcak/jsr/doxygen/html/wrappingS-H-C_8js.html 
and other wrappers.

I am also thinking about the license of the texts that appear on the web. 
Should these be GPL3+, GFDL, or some other license? What does FSF prefer?

Libor