Take the qbs.install* properties into account when change tracking.

These are currently ignored, because we only look for properties that
were requested in prepare scripts. This does not typically happen for
installation parameters, but since they end up in the output artifacts,
changes to them still require re-setting up the respective build data.

Task-number: QBS-359
Change-Id: I571cb4c1a02ea790ddde2f244136c6a0fd6fb627
Reviewed-by: Joerg Bornemann <joerg.bornemann@digia.com>