mathjax/MathJax-src: MathJax v4.1.2

This is mainly a bug fix release that resolves a number of issues from v4.1.1.

The one change that may affect current content is that some of the font-sizing macros like \large and \tiny were setting the wrong sizes, and have been corrected. In particular, the sizes for \tiny and \Tiny were reversed, while the size for \large and the other larger sizes were all off by one size (\large was using the size that should have been for \Large, \Large was using the size of \LARGE, etc.), and \small was too small. These have all been fixed to use the correct sizes. Existing content that use these macros will now use the correct sizing values, and that may affect the results of those expressions. For this reason, we have added a new fontsizev3 TeX package that puts back the incorrect sizing values used in v3 and earlier versions of v4. If you include

window.MathJax = {
  loader: {load: ['[tex]/fontsizev3']},
  tex: {packages: {'[+]': ['fontsizev3']}},
};

in your configuration, you will keep the original sizes. In addition to these size corrections, the missing \SMALL, \Small, and \footnotesize were added, as was a non-standard \HUGE to correspond with the size available (incorrectly) as \Huge in the past.

The issues resolved in v4.1.2 include:

• Have the www.mathjax.org link from the About MathJax dialog open in a new tab. (#1463)

• Properly handle margin-left and margin-right specified on MathML elements. (#1456)

• Fix incorrect layout for bussproofs in CHTML mode for Safari. (mathjax/MathJax#3547)

• Properly handle trailing spaces for \def. (mathjax/MathJax#3550) (#1455)

• Fix problem with sre.style being ignored. (#1453)

• Update font-size macros to correct LaTeX values and make fontsizev3 package for backward compatibility. (#1449)

• Fix CSS for zero-width combining characters in normal variant so it doesn't impact other variants. (#1445)

• Fix several issues with multi-character stretchy assemblies. (mathjax/MathJax#3528, mathjax/MathJax#3531) (#1441)

• Fix problem with \vert becoming stretchy after enrichment. (mathjax/MathJax#3530) (#1440)

• Fix isEmpty() to work with partially complete msubsup elements with empty bases. (mathjax/MathJax#3532) (#1439)

• Fix erroneous definition for --mjx-bg1-color. (#1438)

• Fix several issues with speech generation. (mathjax/MathJax#3551, mathjax/MathJax#3527)

• Improved semantic recognition of multiple prefix/postfix operators and their handling during speech generation.

• Improved enrichment for added operators to better minimise the number of mrow elements added during enrichment.

• Cleanup for relation sign voicing (mainly in English) leading to more concise speech.