Make sure we honor the updates xml checksum flag.

Change-Id: I1fb7aec13c86c1018298d25d186f200c48d1d59e
Reviewed-by: Niels Weber <niels.weber@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Make it possible to calculate dependencies from script.

Task-number: QTIFW-503
Change-Id: Ic359d586f36669d4c1430c22e10b5a209ba6fc3c
Reviewed-by: Samuli Piippo <samuli.piippo@digia.com>
Reviewed-by: Kai Koehne <kai.koehne@digia.com>
Reviewed-by: Niels Weber <niels.weber@digia.com>