Remove large model resources from the build.

+ Remove Qtk::Skybox dependency on Qt resources.

src/designer-plugins/widgetplugincollection.cpp

@@ -37,7 +37,7 @@ WidgetPluginCollection::WidgetPluginCollection(QObject * parent) :
           "Qtk::ToolBox",
           "toolbox.h",
           [](QWidget * parent) { return new Qtk::ToolBox(parent); }),
-      // TODO: Add and test DebugConsole, separate source code into plugins/ dir
+      // TODO: Add and test DebugConsole.
   };
 }