No longer allows symbols of size less than 2mm high or 2mm wide
Enforces correct sizing for Australia Post, Intelligent Mail, Royal Mail 4-State and KIX Code
Adjusts ascender/tracker/descender proportions on all 4-state codes to revised 3/2/3 standards
Enforces normative sizing for UPC and EAN
Enforces minimum sizing for Codabar and Code 49
Tidies up the code a bit so that all of the above makes some sense