[HEADSUP] improvement of error classification script on pointyhat

[Mark Linimon]

If you are not in the habit of looking at the summaries of the results of
port building error logs on the ports build cluster, you can safely ignore
this message.

However, if you are, you will find that the latest changes on pointyhat
have significantly dropped the number of 'false positive' classifications
(specifically, 'makefile' for 'mtree') and also added a few percent more
true positives for what were '???' before.

These results are now reflected in the *-latest build error summaries, and
thus, in that part of portsmon.  The *-full ones have not been updated yet.

mcl