the link label for the classhelp URLs is wrapped in parens
'(%s)'. Letting the caller decide whether he wants to
use parens would be more flexible, as then
I could make some existing text/label a link to the
help popup, instead of having to add a separate label.

Example: I'd prefer

<span ...classhelp(label='Topic'...)/>

over

Topic <span ...classhelp(...)/>