Add missing unitalicized oper's supported by LaTeX

Except ones with over/under lines/arrows, and except the two-word ones
like \injlim and \projlim

http://latex.wikia.com/wiki/List_of_LaTeX_symbols#Named_operators:_sin.2C_cos.2C_etc.
Remove unitalicized oper's not supported by LaTeX

\proj, \span, and \lcm aren't in LaTeX at all.

\mod is apparently pretty special in LaTeX, seems to do stuff with
spacing too:
http://www.artofproblemsolving.com/Wiki/index.php/LaTeX:Commands#Mods
Sort unitalicized fns list alphabetically
Support 2-word unitalicized LaTeX operator names
Comment UnItalicizedCmds list with link #comment