Doc: move Class View plugin docs to .cpp files.

QDoc does not find docs in the .h files.
Use \brief only for namespaces, classes, enums, and properties.
Use standard wording for \brief and \fn.
Use \a and \c according to guidelines.

Fix grammar and style.

Change-Id: Ib685a03c97ef38661ecc156f61d70085514357fc
Reviewed-by: Erik Verbruggen <erik.verbruggen@digia.com>

src/plugins/classview/classviewnavigationwidgetfactory.h

@@ -35,15 +35,6 @@
 namespace ClassView {
 namespace Internal {
 
-/*!
-   \class NavigationWidgetFactory
-   \brief INavigationWidgetFactory implementation for Class View
-
-   INavigationWidgetFactory implementation for Class View. Singleton instance.
-   Supports \a setState publc slot to add/remove factory to \a ExtensionSystem::PluginManager.
-   Also supports some additional signals, \a widgetIsCreated and \a stateChanged.
- */
-
 class NavigationWidgetFactory : public Core::INavigationWidgetFactory
 {
     Q_OBJECT
@@ -81,9 +72,6 @@ public:
     void restoreSettings(int position, QWidget *widget);
 
 signals:
-    /*!
-       \brief Signal which informs that the widget factory creates a widget.
-     */
     void widgetIsCreated();
 };