pgsql-server: Mention plpgsql: < o -Allow parameters to be specified

Log Message:
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Mention plpgsql:

< o -Allow parameters to be specified by name and type during definition

o -Allow PL/pgSQL parameters to be specified by name and type during definition

Modified Files:
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pgsql-server/doc:
TODO (r1.1305 -> r1.1306)
(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/TODO.diff?r1=1.1305&amp;r2=1.1306)