Add a CC0 license.
Rename the text executable to cssparser-tests
Rename the json-tests directory to css-parsing-tests

... same as the remote (git-subtree'd) repository.
Switch the README file to reStructuredText
Add instructions for git-subtree, and an update script.
git-subtree does not like ./ prefixes.
Merge commit '38eb73678490b43ddee7951423a44276f676628f'