[Rd] Bundling MathJax

[Ivan Krylov]

Hello R-devel,

I appreciate the efforts devoted towards improving equation typography
in HTML manuals. Since MathML lost its status as the way to express
mathematics on the web after its removal from Google Chrome in 2013,
MathJax and KaTeX are probably the best options left: both TtH [1] and
HeVeA [2] don't render math quite as well and likely don't do anything
about accessibility of the resulting equations (which seems to be the
reason to focus on the HTML documentation in the first place).

Having seen r81881 [3], I would like to suggest bundling MathJax
together with R instead of loading it from the Internet. Every now and
then, I work from places with spotty Internet connection (e.g. mobile
network on a train). If R defaults to downloading a file every time
Rd2HTML is called, that would be very inconvenient to me, especially
since the requests for external JavaScript could intermittently fail
or take a long time to load, resulting in partially failed renders.

For now, R documentation can be viewed without access to external
resources (admittedly, not counting the use of external \figure{} and
other Rd macros by packages, which is rare). I think that's a major
strength of R and I would like to help preserve it.

-- 
Best regards,
Ivan

[1] http://hutchinson.belmont.ma.us/tth/in_action.html

[2] http://hevea.inria.fr/examples/test/suite.html

[3]
https://github.com/r-devel/r-svn/commit/55e013251cbaf8942d34820f1854c9cfc38e097b