The bugdoc has a table with a single cell, and also a nested table in
that cell. Both tables have auto width. The problem was that the width
of the outer table was too large.

There is a trick in DomainMapperTableManager::startLevel() to get the
cell widths at the correct level: do the same in
DomainMapperTableManager::endLevel(), and that'll fix the table width
problem. (Because with that, the outer table will correctly have access
to its cell width.)

Change-Id: Ib750f0475364fd7e47c445cb54f2df34f3af085d