pgsql: Remove ill-considered (not to mention undocumented) attempt to

Log Message:
-----------
Remove ill-considered (not to mention undocumented) attempt to make
contrib/intarray's GIN opclass override the built-in default.  Per bug #3048
and other complaints.

Tags:
----
REL8_2_STABLE

Modified Files:
--------------
    pgsql/contrib/intarray:
        README.intarray (r1.13 -> r1.13.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/intarray/README.intarray?r1=1.13&r2=1.13.2.1)
        _int.sql.in (r1.22 -> r1.22.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/intarray/_int.sql.in?r1=1.22&r2=1.22.2.1)
        uninstall__int.sql (r1.4 -> r1.4.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/intarray/uninstall__int.sql?r1=1.4&r2=1.4.2.1)
    pgsql/contrib/intarray/expected:
        _int.out (r1.18 -> r1.18.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/intarray/expected/_int.out?r1=1.18&r2=1.18.2.1)
    pgsql/contrib/intarray/sql:
        _int.sql (r1.10 -> r1.10.2.1)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/contrib/intarray/sql/_int.sql?r1=1.10&r2=1.10.2.1)