andrewfn

Issue #1595428 by andrewfn: Make sanitization setable on a format by format basis.

Issue #1595428 by andrewfn: Provide a built-in sanitization option for the Writeup input filter.

Issue #1595406 by andrewfn: Missing and duplicate tags in sanitization function.

Issue #1595406 by andrewfn: Missing and duplicate tags in sanitization function.