RegularCommand can also take NestedLiteral parameters

[retorquere]

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[retorquere]

Just a heads-up -- I've made further changes to the grammar because to get verbatim parsing and proper argument consumption right. Some of these changes I figure may not align with how you want to approach things -- for one, my grammar needs to know a lot more about what it's parsing. Some of this could in principle be post-cleaned on a simpler AST (as was produced by the last changes I offered for astrocite) but it was just easier to do inside the grammar. I do think that the current grammar coupled with my post processing is currently best in class outside actually running it through a latex stack. Notable changes in behavior:

• commands now only consume the arguments they expect -- previously \url would consume all NestedLiterals that followed it. It now consumes exactly one.
• stuff like \frac 1 2 now works (I know, ugly, but actually used)
• < has a different meaning depending on whether it's in text mode or math mode, which is now handled
• Commands like url and href parse their arguments in verbatim mode

The changed grammar lives here, and the postprocessor here.

I wouldn't half mind if I could just maintain the bibtex parser in that repo, and have astrocite consume either just the grammar or the grammar + postprocessor. I have a pretty extensive testsuite so I have a vested interest in keeping my parser stable yet updated for new bug reports I get.