When a tabbar had a large number of tabs with short text (5 to 7 characters), no eliding would happen, the window would keep growing until it became wider than the desktop. This commit therefore reduces the minimumSizeHint using more aggressive eliding when eliding is enabled. Also, at some point I had doubts about whether minimumSizeHint took eliding into consideration at all, so I also added a unit-test for minimumSizeHint and sizeHint of tabbars, in various modes. Merge-request: 583 Reviewed-by: Olivier Goffart <olivier.goffart@nokia.com>