qbs project files: Fix references to non-existing properties.

Change-Id: I653231939a9495395cbe36de26b67e1535d2169e
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>
Debugger: Rework detection of SDK-specified "auto" debuggers

Change-Id: I173752a41da7b34d64cb7e3e423992be464fc73b
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@digia.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>