Spreadsheet RegExp

I'm so tired of debugging spreadsheets. Thankfully, it all works now.

Also, I have been writing a lab report and many of my fixes are related
to that.
-Went back to Spin.js partially because it breaks things otherwise.
Legacy code must remain.
-Cleaned up unneeded content whitespace
-Better line separation detection
-Divs and kbds both exist as full internal components that aren't
separable
-Fixed literally the weirdest latex bug with fractions
-Format item text fields are longer
-Both spreadsheet variables and spreadsheet functions work and execute
correctly
-More LaTeX commands added to reference (though I really should get a
better way of organizing them
-Dictionary has new loader
-Large popups are now even larger
-Other minor bug and UX fixes