This adds some resource-ownership tracking.

Time to start spreading this out, more.

dw/fltkui.hh

@@ -5,6 +5,8 @@
 #   error Do not include this file directly, use "fltkcore.hh" instead.
 #endif
 
+#include <memory>
+
 #include <FL/Fl_Button.H>
 #include <FL/Fl_Menu.H>
 #include <FL/Fl_Text_Buffer.H>
@@ -284,7 +286,7 @@ protected:
    Fl_Widget *createNewWidget (core::Allocation *allocation);
 
 public:
-   FltkComplexButtonResource (FltkPlatform *platform, dw::core::Widget *widget,
+   FltkComplexButtonResource (FltkPlatform *platform, std::unique_ptr< dw::core::Widget > widget,
                               bool relief);
    ~FltkComplexButtonResource ();
 };