pgpool with master/slave

I have added the attached documentation patch to explain how
master/slave can be combined with pgpool to avoid the problems with
non-deterministic functions. You can read more details here:

http://momjian.us/main/blogs/pgblog/2010.html#April_26_2010_2

--
Bruce Momjian <bruce@momjian.us> http://momjian.us
EnterpriseDB http://enterprisedb.com