There are no actual license changes (or at least I tried to avoid them
by reading the `git diff`) and I added the lines missing from GitHub
selector, even if I have no idea where they originate from (the two last
ones).
* Change copyright timestamps
* LICENCE.md: cut `git shortlog` to two lines and add `ne`.
* README.md: increase topic levels.
* oidentd.conf: remove Windows line-ending(?) (so that is what it was).
* xsessionrc: update PATH.