(bug 4897) Nonfree version of new hook for CC warning

the hook is called in the dw-free patch accompanying. THIS IS NOT
TESTED, since my 'hack isn't set up to do payments, so it may not work
or the formatting may be weird!
Merge pull request #27 from rahaeli/bug4897-nf

(bug 4897) Nonfree version of new hook for CC warning