- warn about fields applied twice (program error)
- warn about fields not used (configuration error)
- add operator<< for "clean" looking preset application
Build up the list of known presets by what the Config-object
expects, not by what the Config file provides. This allows
early detection of mis-matched configurations.
Presets can only apply to Q_PROPERTY properties, and the
preset must match the property name.
This adds support for checking whether a field is editable;
Config objects should reject changes if the field is not
editable. There is an "unlock" setting to override the
check, although this is currently always locked.
