Welcome page: Set size constraint on the container widget.
Welcome page: Set size constraint on the container widget.

Such that QLayout properly handles it. Fixes warnings about
resizing violating size constraints on Windows.

Task-number: QTCREATORBUG-10251

Change-Id: I25361fbc994f23d5616c240663d64f8b3474e7f7
Reviewed-by: Thomas Hartmann <588ee739c05aab7547907becfd1420d2b7316069@digia.com>

richardmg/qtcreator,maui-packages/qt-creator,AltarBeastiful/qt-creator,martyone/sailfish-qtcreator,Distrotech/qtcreator,kuba1/qtcreator,maui-packages/qt-creator,kuba1/qtcreator,AltarBeastiful/qt-creator,farseerri/git_code,darksylinc/qt-creator,kuba1/qtcreator,xianian/qt-creator,danimo/qt-creator,omniacreator/qtcreator,danimo/qt-creator,amyvmiwei/qt-creator,kuba1/qtcreator,farseerri/git_code,darksylinc/qt-creator,martyone/sailfish-qtcreator,danimo/qt-creator,Distrotech/qtcreator,xianian/qt-creator,Distrotech/qtcreator,martyone/sailfish-qtcreator,omniacreator/qtcreator,Distrotech/qtcreator,AltarBeastiful/qt-creator,xianian/qt-creator,farseerri/git_code,farseerri/git_code,martyone/sailfish-qtcreator,colede/qtcreator,kuba1/qtcreator,AltarBeastiful/qt-creator,darksylinc/qt-creator,omniacreator/qtcreator,xianian/qt-creator,colede/qtcreator,martyone/sailfish-qtcreator,colede/qtcreator,maui-packages/qt-creator,darksylinc/qt-creator,xianian/qt-creator,danimo/qt-creator,martyone/sailfish-qtcreator,amyvmiwei/qt-creator,xianian/qt-creator,farseerri/git_code,kuba1/qtcreator,colede/qtcreator,xianian/qt-creator,kuba1/qtcreator,danimo/qt-creator,farseerri/git_code,amyvmiwei/qt-creator,kuba1/qtcreator,darksylinc/qt-creator,darksylinc/qt-creator,amyvmiwei/qt-creator,richardmg/qtcreator,danimo/qt-creator,AltarBeastiful/qt-creator,AltarBeastiful/qt-creator,colede/qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,amyvmiwei/qt-creator,richardmg/qtcreator,Distrotech/qtcreator,richardmg/qtcreator,danimo/qt-creator,richardmg/qtcreator,amyvmiwei/qt-creator,martyone/sailfish-qtcreator,richardmg/qtcreator,xianian/qt-creator,maui-packages/qt-creator,maui-packages/qt-creator,martyone/sailfish-qtcreator,AltarBeastiful/qt-creator,darksylinc/qt-creator,farseerri/git_code,colede/qtcreator,Distrotech/qtcreator,omniacreator/qtcreator,omniacreator/qtcreator,maui-packages/qt-creator,farseerri/git_code,omniacreator/qtcreator,maui-packages/qt-creator,colede/qtcreator,amyvmiwei/qt-creator,AltarBeastiful/qt-creator,omniacreator/qtcreator,richardmg/qtcreator,kuba1/qtcreator,amyvmiwei/qt-creator,Distrotech/qtcreator,danimo/qt-creator,darksylinc/qt-creator,danimo/qt-creator