* gnu/packages/patches/mathjax-4.0.0-disable-webpack.patch,
gnu/packages/patches/mathjax-4.0.0-no-a11y.patch: New files.
* gnu/local.mk (dist_patch_DATA): Record them.
* gnu/packages/javascript.scm (js-mathjax-4): New variable.
(js-mathjax-for-r-mathjaxr): Define as alias for js-mathjax-4.
Change-Id: I156605a8d11d615489d8f0c0c267c96339afc3c7
