pgsql: Back out SQLSTATE and SQLERRM support.

Log Message:
-----------
Back out SQLSTATE and SQLERRM support.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        plpgsql.sgml (r1.68 -> r1.69)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plpgsql.sgml.diff?r1=1.68&r2=1.69)
    pgsql/src/pl/plpgsql/src:
        gram.y (r1.71 -> r1.72)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/gram.y.diff?r1=1.71&r2=1.72)
        pl_exec.c (r1.140 -> r1.141)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/pl_exec.c.diff?r1=1.140&r2=1.141)
        plpgsql.h (r1.59 -> r1.60)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpgsql/src/plpgsql.h.diff?r1=1.59&r2=1.60)
    pgsql/src/test/regress/expected:
        plpgsql.out (r1.30 -> r1.31)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/expected/plpgsql.out.diff?r1=1.30&r2=1.31)
    pgsql/src/test/regress/sql:
        plpgsql.sql (r1.25 -> r1.26)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/test/regress/sql/plpgsql.sql.diff?r1=1.25&r2=1.26)