CMake improvements

A few improvements mainly in the context of multi-configuration generators:

• Creating Windows installation failed if dependend libraries are installed for multiple configurations
• Windows installation did not respect whether TIFF was deselected in the options
• Disabling Qt debug output was not working for multi-configurations
• added a few messages to show generator info
• rectified messages to work with multi-configurations
• allow "Edit and continue" in Windows debug configuration
• reduce library import clutter of dependent targets (make libraries "PRIVATE" when only internally used by the imported target)