pgsql: Add table_name and table_schema to plperl trigger data.

Log Message:
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Add table_name and table_schema to plperl trigger data. relname is
kept but now deprecated. Patch from Adam Sjøgren. Add regression test to
show plperl trigger data (Andrew).
TBD: apply similar changes to plpgsql, plpython and pltcl.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        plperl.sgml (r2.52 -> r2.53)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plperl.sgml.diff?r1=2.52&r2=2.53)
    pgsql/src/pl/plperl:
        plperl.c (r1.108 -> r1.109)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/plperl.c.diff?r1=1.108&r2=1.109)
    pgsql/src/pl/plperl/expected:
        plperl_trigger.out (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/expected/plperl_trigger.out.diff?r1=1.1&r2=1.2)
    pgsql/src/pl/plperl/sql:
        plperl_trigger.sql (r1.1 -> r1.2)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plperl/sql/plperl_trigger.sql.diff?r1=1.1&r2=1.2)