Adding textcase.sty test

[dginev]

I was using this test to develop, but now that @brucemiller beat me to the punchline, I'm offering it as a PR to ward off regressions

[brucemiller]

Cool! But as long as you're testing, wouldn't it be good to embed some of the special junk (math, \ref,..) that cause it to split into separate \uppercases?

[dginev]

Good call with adding the complex cases. I updated with the documentation examples from CTAN at:
http://mirrors.nxthost.com/ctan/macros/latex/contrib/textcase/textcase.pdf

And regenerated the PDF and XML for the new test. I noticed two problems when inspecting by hand:

• Unicode macro seem iffy - \ae was capitalized in the PDF, but not in the XML
• Citations are left unfilled during core processing so the trick with renewing the \citeform macro is a no-op for latexml, and the citation text's case remains unchanged. The parts that get filled during the core processing are capitalized correctly.

But at least no errors and meaningful output! And tables, environments, math and nested groups seem to work ok.

[dginev]

I think I'm ready to get back to PR comments.

I pushed a commit that fixes the \ae capitalization issue, but at the cost of the custom binding for the latex-native \MakeUppercase and \MakeLowercase macros regressing.

Interestingly if I replace the binding with the raw code from latex.ltx they work again!

So feel free to examine my last commit, which should entirely fix the macro capitalization issue.

As to the citation-specific parts - it is a limitation we should probably ignore for now, until we want to model it explicitly, as you mentioned via email. Could be good to merge!