Graceful degradation in case of legacy browser?

[cure53]

We might want to think about what happens, when the browser running a purified website is not supporting what DOMPurify needs.

Should we just return the original string? Or are we in a position to modify something?

[cure53]

That should do and tests pass. Any thoughts?

        /* Feature check and untouched opt-out return */
        if(typeof document.implementation.createHTMLDocument === 'undefined') {
            return dirty;    
        }