When grouping in BIRT, we frequently want the grouping
value to show up on the first line as follows:

Group   User                       Reputation
------  ---------------            ----------
Admins  Bill The Weasel                51,018
        Mark Grovel                   118,101
Users   Pax_my_bags_got_to_go          73,554
        Jon Scoot                  **,***,*** <- overflow
        Clueless                       92,928

The normal way of achieving this is to lay out the group in the
designer as follows:

        +---------+--------+--------------+
Tbl Hdr | Group   | User   |   Reputation |
        +---------+--------+--------------+
Grp Hdr | [Group] |        |              |
        +---------+--------+--------------+
Grp Dtl |         | [User] | [Reputation] |
        +---------+--------+--------------+
Grp Ftr |         |        |              |
        +---------+--------+--------------+
Tbl Ftr |         |        |              |
        +---------+--------+--------------+

which, unfortunately, lays out the data in exactly that way, with
the grouped value on a different line:

Group   User                       Reputation
------  ---------------            ----------
Admins
        Bill The Weasel                51,018
        Mark Grovel                   118,101
Users
        Pax_my_bags_got_to_go          73,554
        Jon Scoot                  **,***,*** <- overflow
        Clueless                       92,928

This is particularly painful with data where there's lots of
groups with only one user since we use twice as much
space as needed. If we move the [Group] data item down
to the Grp Dtl line, we get it printed for every line in the group.

How, in BIRT, do we merge the two lines Grp Hdr and the
first Grp Dtl?