removing the math zoom feature

[pkra]

We re-implemented the zoom via MathJax at AmerMathSoc/AMS-Lens#29. This fixes several bugs and, philosophically, seems the better place to have it. But now we have two zooms and they can clash.

I would like to propose to remove the zoom feature from the math extension.

I'm happy to make the necessary changes but would like to hear if there's a chance it will get merged.

[pkra]

An alternative option / compromise might be to have a generic shrink/zoom feature, not just for math but for other elements (e.g., tables).

[pkra]

Just to make a note here. I've implemented a scale/zoom feature for AMS Lens. This could probably be made content agnostic (e.g., support all MathJax output, both server and client-side MathJax, other forms of HTML-math) if there's interest.

I'm unable to properly re-write Lens's formula-zoom extension though. I don't claim to understand the internal flow, but following the existing code, I could get most of the way -- except for the initial fitFormula call. IIUC the current code depends on the fact that MathJax's signal will come in after Lens is finished, but only because it is slower than Lens, i.e., it's basically a racing condition. Now that's not a problem with client-side MathJax but if that's not around, this won't work. I couldn't figure out if Lens has some signalling for being done with its rendering so I'm currently listening to the body class names which seems like a terrible idea. Is there a signaling method I missed?