TreeModel: Add good old ModelTest's code
TreeModel: Add good old ModelTest's code

Currently #if'd out, but takes only a one line change to enable
quick testing. Tests pass with the included change to flags().

Change-Id: I6dca376f162ad26e8ce6de65241e56497ff7267e
Reviewed-by: Christian Stenger <accbb51712d7b9c4fb108439d01e716148e5f9e6@theqtcompany.com>

amyvmiwei/qt-creator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,Distrotech/qtcreator,xianian/qt-creator,xianian/qt-creator,Distrotech/qtcreator,xianian/qt-creator,amyvmiwei/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,danimo/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,xianian/qt-creator,AltarBeastiful/qt-creator,xianian/qt-creator,kuba1/qtcreator,martyone/sailfish-qtcreator,danimo/qt-creator,xianian/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,xianian/qt-creator,martyone/sailfish-qtcreator,Distrotech/qtcreator,xianian/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,danimo/qt-creator,kuba1/qtcreator,xianian/qt-creator,amyvmiwei/qt-creator,danimo/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,kuba1/qtcreator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,farseerri/git_code,farseerri/git_code,kuba1/qtcreator,danimo/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,kuba1/qtcreator,danimo/qt-creator,Distrotech/qtcreator,farseerri/git_code,kuba1/qtcreator,kuba1/qtcreator,danimo/qt-creator,kuba1/qtcreator,farseerri/git_code,Distrotech/qtcreator,martyone/sailfish-qtcreator,farseerri/git_code,farseerri/git_code,AltarBeastiful/qt-creator,Distrotech/qtcreator