Clarify dynamic pl/pgsql item and add URLs. Restructure server-side

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