Add thread stack size fix by Andrew.

doc/PLATFORMS/BSD.txt

+Steps to building python for use with Zope on FreeBSD to avoid
+segmentation faults (by Andrew Sawyers for Pythons up to 2.3).
+
+The default thread stack size for FreeBSD is too small; when building
+Python for use with Zope it is often necessary to increase the thread
+stack size to avoid segmentation faults. There are two ways which you
+can increase the default python thread stack size.
+
+Way #1: In your Python source directory:
+
+    * >cd Python
+    * >edit thread_pthreads.h
+
+      at the top of the header file, add #define THREAD_STACK_SIZE 1000000
+    * >save
+    * >cd ..; ./configure
+
+Way #2: In your Python source directory:
+
+    * >./configure
+    * >make OPT="-DNDEBUG -g -O3 -Wall -Wstrict-prototypes -DTHREAD_STACK_SIZE=1000000"
+
+Passing in the define or adding the define to your source solves all
+experiences I have experienced with Zope segfaulting while running on
+my FreeBSD platforms.