Add latex output mode

[Klap-in]

• add some replacements from the LaTeXit plugin
• return latex in latex output mode
• add some PHPDocs

This extends the Mathjax plugin, such that https://github.com/Wrent/dokuwiki-plugin-latexit/issues/19 can be completed.

[liffiton]

Thanks for the clean-up and updates! I'm a bit wary of modifying the content in handle(), as I imagine if one is writing code within math delimiters, they'll know to write it in TeX, but I also see why you might want that. I'll keep it in as long as it doesn't cause problems for anyone else. Also, I don't have a setup to test the $mode == 'latex' part, so I'll just trust that that is doing something useful. :)

[Klap-in]

Latex mode is used for latex exports like the mentioned latexit plugin.

I doubt for the same reasons. I will ask the author of the latexit plugin for the reasoning of adding it. Most work done so far was reordening of the functionality between the mathjax and latexit plugins.

I thought that LaTeX has no default syntax conflicts with this syntax, has it? Therefore I consider it as save addition, without risks of breaking current latex instructions.

[liffiton]

Yes, I do think it's relatively safe as well, but each of those strings is valid TeX, and though they are unlikely to be used, it's possible someone might want, e.g., <=> to actually render as those three characters.

But again, I think it's fine for now. I assume someone had added those translations elsewhere for a particular reason, and it's less likely that there is someone who will see them as a problem.