Remembering tweaks for ports?

[Dan Swartzendruber]

Forgive me if this has been asked before.  Is there any way to not have to 
re-customize ports whenever you do an upgrade?  One that is particularly 
annoying to me is the interaction between amavisd-new and clamav.  When 
clamav is installed (even via portupgrade), it sets ownership (uid and gid) 
of various directories to clamav:clamav.  Unfortunately, amavisd-new wants 
vscan:vscan.  I found this out the hard way when I did the initial install, 
but every time clamav port is upgraded, I have to go tweak the same 
directories.  Am I missing something here?