based on 4.1.3 update from Steve Shockley <steve.shockley@shockley.net>
prompted by Bert Koelewijn <bert@schmidt-koelewijn.nl>
ok espie@ "no actual risk you'll break it more"
At one point bsd.port.mk put out erroneous PLIST-auto, with @cwd, @pkgname,
and @pkgdep lines.
These are actually added by make package, and shouldn't usually be put
inside the PLIST, as this is extra information to update.
I left a few @cwd in, mainly for the perl modules, which want to live under
/usr to work.
