Prepend transpiled symbolic constant names with % sign

[andstor]

For maxima to calculate with symbolic constants, they need to be prepended with a % sign.
See the Maxima documentation on Functions and Variables for Constants.

The symbolic constants should be handled as macros. See the macros.js file, and the doToken() function.

Expected behavior

Input	Output
	onlyGreekName	onlyGreekSymbol
e	%e
i	%i
\gamma	%gamma	γ
\phi	%phi	ϕ
\pi	%pi	π