pgsql: Clarify dynamic pl/pgsql item and add URLs.

Log Message:
-----------
Clarify dynamic pl/pgsql item and add URLs. Restructure server-side
section into PL/pgSQL and non-PL/pgSQL sections:

< o Fix PL/pgSQL RENAME to work on variables other than OLD/NEW
< o Allow function parameters to be passed by name,
< get_employee_salary(emp_id => 12345, tax_year => 2001)
< o Add Oracle-style packages
< o Add table function support to pltcl, plpython
< o Add capability to create and call PROCEDURES
< o Allow PL/pgSQL to handle %TYPE arrays, e.g. tab.col%TYPE[]
< o Allow function argument names to be statements from PL/PgSQL
< o Add MOVE to PL/pgSQL
< o Add support for polymorphic arguments and return types to
< languages other than PL/PgSQL
< o Add support for OUT and INOUT parameters to languages other
< than PL/PgSQL
< o Add single-step debugging of PL/PgSQL functions
< o Allow PL/PgSQL to support WITH HOLD cursors
< o Allow PL/PgSQL RETURN to return row or record functions
<
< http://archives.postgresql.org/pgsql-patches/2005-11/msg00045.php
> o PL/pgSQL
> o Fix RENAME to work on variables other than OLD/NEW
> o Allow function parameters to be passed by name,
> get_employee_salary(emp_id => 12345, tax_year => 2001)
> o Add Oracle-style packages
> o Allow handling of %TYPE arrays, e.g. tab.col%TYPE[]
> o Allow listing of record column names, and access to
> record columns via variables, e.g. columns := r.(*),
> tval2 := r.(colname)
>
> http://archives.postgresql.org/pgsql-patches/2005-07/msg00458.php
> http://archives.postgresql.org/pgsql-patches/2006-05/msg00302.php
> http://archives.postgresql.org/pgsql-patches/2006-06/msg00031.php
>
> o Add MOVE
> o Add single-step debugging of functions
> o Add support for WITH HOLD cursors
> o Allow PL/RETURN to return row or record functions
>
> http://archives.postgresql.org/pgsql-patches/2005-11/msg00045.php
>
>
> o Other
> o Add table function support to pltcl, plpython
> o Add support for polymorphic arguments and return types to
> languages other than PL/PgSQL
> o Add capability to create and call PROCEDURES
> o Add support for OUT and INOUT parameters to languages other
> than PL/PgSQL

Modified Files:
--------------
pgsql/doc:
TODO (r1.1878 -> r1.1879)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/TODO.diff?r1=1.1878&r2=1.1879)
pgsql/doc/src/FAQ:
TODO.html (r1.381 -> r1.382)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/FAQ/TODO.html.diff?r1=1.381&r2=1.382)