pgsql: Add: > * Allow INSERT/UPDATE ...

Log Message:
-----------
Add:

* Allow INSERT/UPDATE ... RETURNING inside a SELECT 'FROM' clause

http://archives.postgresql.org/pgsql-general/2006-09/msg00803.php
http://archives.postgresql.org/pgsql-hackers/2006-10/msg00693.php

Modified Files:
--------------
pgsql/doc:
TODO (r1.2102 -> r1.2103)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.2102&r2=1.2103)
pgsql/doc/src/FAQ:
TODO.html (r1.603 -> r1.604)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.603&r2=1.604)