Make cmod::Model destructor virtual (Closes: #8)

+tiny warning fixes

src/celengine/meshmanager.cpp

@@ -528,11 +528,13 @@ ConvertTriangleMesh(M3DTriangleMesh& mesh,
 }
 
 
+#if 0
 static Material::Color
 toMaterialColor(Color c)
 {
     return {c.red(), c.green(), c.blue()};
 }
+#endif
 
 
 static Model*

src/celestia/qt/qtcolorswatchwidget.cpp

@@ -14,7 +14,7 @@
 #include <QColorDialog>
 
 
-ColorSwatchWidget::ColorSwatchWidget(const QColor& c, QWidget* parent) :
+ColorSwatchWidget::ColorSwatchWidget(const QColor& c, QWidget* /*parent*/) :
     QLabel(nullptr),
     m_color(c)
 {
@@ -43,4 +43,3 @@ void ColorSwatchWidget::mouseReleaseEvent(QMouseEvent* /*unused*/)
     if (c.isValid())
         setColor(c);
 }
-

src/celmodel/model.h

@@ -32,7 +32,7 @@ class Model
 {
  public:
     Model();
-    ~Model();
+    virtual ~Model();
 
     const Material* getMaterial(unsigned int index) const;
     void setMaterial(unsigned int index, const Material* material);