In some situations we can get into resizeSections in a hidden
QHeaderView. If the headerView is hidden then we look at all the
rows, and that can be extemely expensive for a large model.
This patch limits the sizeHint with only looking at a maximum
1000 rows. Though this is more inaccurate it is also faster -
and it is not much different from what QTreeView does.
Change-Id: Ief4b54c5a3c5a0db02e8b595c9b9b3162633ee67
Reviewed-by: Stephen Kelly <stephen.kelly@kdab.com>