This reverts commit 28f4d8513db7efce17bfd8b80fa7c8b237fd1c18.
The original revert was to revert an accidental merge from master to 4.7. This now reverts the revert on Master, so that we still have those changes on Master.
With the caveat that the qtQuickControls had to be updated to 2.3, due to a qt bug in 1.x that did
not update the dropdown popup list according to the ListModel.
This leads to a different look in the dropdowns and in the buttons of the open project dialog,
compaired to the rest of the application.
CURA-7609
