UTF8 for docs

Our release.sgml contains these lines, that I wrote:

        we cannot use UTF8 because SGML Docbook does not support it

        do not use numeric _UTF_ numeric character escapes (&#nnn;),
        we can only use Latin1

        Example: Alvaro Herrera is Álvaro Herrera

Should this be changed now that we are using XML for head?  It cannot be
changed for back branch releases since those are still SGML, so I
suggest we keep this restriction.  I have updated the doc comments.

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

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +