Update CVS documentation to be more current and add documentation about

git mirror.

Remove information about cvsup and documentation that's more about cvs
than our use of cvs.

Backpatch to 8.4 so we get the git information up on the website as
soon as possible.

doc/src/sgml/installation.sgml

-<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.328 2009/12/02 14:07:25 momjian Exp $ -->
+<!-- $PostgreSQL: pgsql/doc/src/sgml/installation.sgml,v 1.329 2009/12/07 19:19:56 mha Exp $ -->
 
 <chapter id="installation">
  <title><![%standalone-include[<productname>PostgreSQL</>]]>
@@ -354,6 +354,11 @@ su - postgres
    Change into that directory for the rest
    of the installation procedure.
   </para>
+
+  <para>
+   You can also get the source directly from the version control repository, see
+   <xref linkend="cvs">.
+  </para>
  </sect1>
 ]]>