Remove all mentions of wxGauge shadow width and bezel face.

The shadow width was only used by wxMotif and bezel face not used at all since
a very, very long time, so just remove these methods from the ports which still
had them (just doing nothing) and remove support of the corresponding XRC
attributes.

include/wx/gauge.h

@@ -80,16 +80,22 @@ public:
     // simple accessors
     bool IsVertical() const { return HasFlag(wxGA_VERTICAL); }
 
-    // appearance params (not implemented for most ports)
-    virtual void SetShadowWidth(int w);
-    virtual int GetShadowWidth() const;
-
-    virtual void SetBezelFace(int w);
-    virtual int GetBezelFace() const;
-
     // overridden base class virtuals
     virtual bool AcceptsFocus() const wxOVERRIDE { return false; }
 
+    // Deprecated methods not doing anything since a long time.
+    wxDEPRECATED_MSG("Remove calls to this method, it doesn't do anything")
+    void SetShadowWidth(int WXUNUSED(w)) { }
+
+    wxDEPRECATED_MSG("Remove calls to this method, it always returns 0")
+    int GetShadowWidth() const { return 0; }
+
+    wxDEPRECATED_MSG("Remove calls to this method, it doesn't do anything")
+    void SetBezelFace(int WXUNUSED(w)) { }
+
+    wxDEPRECATED_MSG("Remove calls to this method, it always returns 0")
+    int GetBezelFace() const { return 0; }
+
 protected:
     virtual wxBorder GetDefaultBorder() const wxOVERRIDE { return wxBORDER_NONE; }