Initial import
Remove import-dialogs

QtQuick.Dialogs was moved to qtquickcontrols
Remove import-privatewidgets
Add qtquickwidgets and qtquickwidgets-devel
Try to fix armv6l build

The trick to pass -mno-thumb doesn't seem to work, the armv6l build
fails with:

    Error: selected processor does not support Thumb mode

Let's see what happens without tampering with gcc flags.
Update to 5.3.1
Remove v8 bdep
Remove -mno-thumb on ARM
Refactor packaging for gbs
Cleanup packaging