This is the update to version 2.7.1. It affects nearly all the files since they copyright and version numbers were updated. It also includes the latests.js file, which allows loading the latest version from cdnjs, rawgit, or jsdelivr (whichever one it was loaded from). It also includes the accessibility extensions in extensions/a11y, and the new mhchem extension in extensions/TeX/mhchem3, since these can be loaded automatically by the core MathJax.
I've smoke tested the release using rawgit.com, and all seems well.