Remove Qt 4 scopes in .pro files

Change-Id: I8e0793700196ea49e06a5c46731afd258f6443c3
Reviewed-by: Jarek Kobus <jaroslaw.kobus@digia.com>
Fix broken tools after switching to QFileDevice.

Follow up on 924ebcdbc9b9e590a5f0905941e2d05ac34d4be2 (Part 1).
Get rid of KDSaveFile, reuse QTemporaryFile. After changing
KDSaveFile to inherit from QFileDevice, it turns out to be not
working properly anymore and crashing e.g. binarycreator while
using it. To save fixing it we just switch to QTemporaryFile.

Change-Id: I785a04db91b431f5e122f193ecf2ef3c54e34b1c
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Revert change from QIODevice to QFileDevice.

Follow up on 924ebcdbc9b9e590a5f0905941e2d05ac34d4be2 (Part 2).
Remove some unused methods. Cleanup some unused code. Add some
documentation what the Archive class does and is used for. Add
copy method and switch back the class to inherit from QIODevice
as also the Archive class does not work as QFileDevice descent.

Change-Id: Ia20f02c5aa53ba977fdc1d14785031b0cfbce386
Reviewed-by: Kai Koehne <kai.koehne@digia.com>