[Pan-users] Build fail during configure FreeBSD 9.3

[Dave]

Pan fails during the configure stage when building from ports on FreeBSD 9.3

It's checking for zlib and fails to find zlib.pc

zlib.pc exists on a 10.3 box but not on 9.3.

Am I missing zlib.pc and if so how to find/install it?  Or is it a FreeBSD 10 
thing and I have to either upgrade from 9.3 or somehow fix the Pan 
Makefile/patch files to find zlib some other way? ( I doubt I could manage that 
on my own!)

It's not a huge problem for as I will be upgrading my main PC to 10.3 
eventually, but I do prefer to build the port rather than install the package 
because I increase the limits on news server threads.