fix caret issue

include/nana/gui/basis.hpp

@@ -273,6 +273,7 @@ that return a corresponding nana::appearance with predefined values.
 	public:
 		virtual ~caret_interface() = default;
 
+		virtual bool activated() const = 0;
 		virtual void disable_throw() noexcept = 0;
 
 		virtual void effective_range(const rectangle& range) = 0;

include/nana/gui/detail/basic_window.hpp

@@ -55,6 +55,7 @@ namespace detail
 		void dimension(const size& s) override;
 		void visible(bool visibility) override;
 		bool visible() const override;
+		bool activated() const override;
 	private:
 		basic_window * owner_;
 		point	position_;