Remembering defines for port upgrades.

[Adam Fabian]

I've been sticking options like WITHOUT_TTF_BYTECODE_ENABLED=yes (for
freetype2) in /etc/make.conf.  It's been working, for the actual
building of the port.  The downshot is that it seems to drive the
package tools nuts. (portupgrade makes strange errors, make index
fails).  Is there any other/better way to remember build options so
that I don't have to remember them every time I build a port?

It's also possible that I've confused legitimate, tuneable knobs with
some kinds of reserved variables.  The suspect ones are USE_X11,
USE_ATHENA (but I specifically remember using that one for vim), and
USE_OPENSSL.

-- Adam Fabian (afabian at austin.rr.com)