Moved Model::EnableDraw to SceneNode::EnableDrawing

Same goes for Model::IsDrawEnabled() => SceneNode::IsDrawingEnabled()
Is Drawable is now a pure virtual method from SceneNode


Former-commit-id: 217c6a21a98206ee0b283aaa216d419696a70faf

include/Nazara/Graphics/Light.hpp

@@ -36,6 +36,8 @@ class NAZARA_API NzLight : public NzSceneNode
 		nzSceneNodeType GetSceneNodeType() const;
 		NzColor GetSpecularColor() const;
 
+		bool IsDrawable() const;
+
 		void SetAmbientColor(const NzColor& ambient);
 		void SetAttenuation(float attenuation);
 		void SetDiffuseColor(const NzColor& diffuse);