+ *
+ * A derived class needs to keep track of its changed state. Whenever a child widget changes, it needs to be
+ * compared to its value in permanent storage, and the changed state updated accordingly by calling setChangedState().
+ * For most standard widgets, SettingsPage can do this automatically if desired. Such a child widget needs to have
+ * a dynamic property \c settingsKey that maps to the key in the client configuration file. This key is appended
+ * to settingsKey(), which must be set to a non-null value in a derived class. If the widget's key starts with '/',
+ * its key is treated as a global path starting from the root, rather than from settingsKey().
+ * A second dynamic property \c defaultValue can be defined in child widgets as well.
+ *
+ * For widgets requiring special ways for storing and saving, define the property settingsKey and leave it empty. In this
+ * case, the methods saveAutoWidgetValue() and loadAutoWidgetValue() will be called with the widget's objectName as parameter.
+ *
+ * SettingsPage manages loading, saving, setting to default and setting the changed state for all automatic child widgets.
+ * Derived classes must be sure to call initAutoWidgets() *after* setupUi(); they also need to call the baseclass implementations
+ * of load(), save() and defaults() (preferably at the end of the derived function, since they call setChangedState(false)).
+ *
+ * The following widgets can be handled for now:
+ * - QGroupBox (isChecked())
+ * - QAbstractButton (isChecked(), e.g. for QCheckBox and QRadioButton)
+ * - QLineEdit, QTextEdit (text())
+ * - QComboBox (currentIndex())
+ * - QSpinBox (value())