Hi!

I switched recently from bogofilter to CRM114 and when I tried to sort
the summary of my spam group by the article spam score assigned by
CRM114, I couldn't made it to work.  The spam score of every article
showed up as 0.00 in the summary buffer.

One of the problems seems to be that the spam-necessary-extra-headers
function on spam.el only deals with SpamAssassin and Bogofilter.  I
guess that the header added by the CRM114 filter should be added to
the list of extra headers, also.

Once that is fixed, there remains another problem in the
spam-extra-header-to-number function, which already extracts the
proper score from the CRM114 header, but returns a string instead of a
number.

I include below a patch against spam.el that fixes both these errors.