Use wxBitmapBundle for AUI tab pages bitmaps

Take wxBitmapBundle instead of just wxBitmap in various public functions
and select the bitmap appropriate for the current DPI scaling when we
need to use it.

Note that this removes wxAuiScaleBitmap() which used custom scaling
logic that might be better than the generic approach used by
wxBitmapBundle, and so could result in a temporary regression in the
icons appearance in high DPI, but they will hopefully be replaced with
SVG versions soon, so that this shouldn't matter.

interface/wx/aui/auibook.h

@@ -139,7 +139,7 @@ public:
     */
     bool AddPage(wxWindow* page, const wxString& caption,
                  bool select = false,
-                 const wxBitmap& bitmap = wxNullBitmap);
+                 const wxBitmapBundle& bitmap = wxBitmapBundle());
 
     /**
         Adds a new page.
@@ -272,7 +272,7 @@ public:
     bool InsertPage(size_t page_idx, wxWindow* page,
                     const wxString& caption,
                     bool select = false,
-                    const wxBitmap& bitmap = wxNullBitmap);
+                    const wxBitmapBundle& bitmap = wxBitmapBundle());
 
     /**
         Inserts a new page at the specified position.
@@ -326,9 +326,9 @@ public:
 
     /**
         Sets the bitmap for the page.  To remove a bitmap from the tab caption, pass
-        wxNullBitmap.
+        an empty wxBitmapBundle.
     */
-    bool SetPageBitmap(size_t page, const wxBitmap& bitmap);
+    bool SetPageBitmap(size_t page, const wxBitmapBundle& bitmap);
 
     /**
         Sets the image index for the given page. @a image is an index into
@@ -445,7 +445,7 @@ public:
     wxWindow* window;     // page's associated window
     wxString caption;     // caption displayed on the tab
     wxString tooltip;     // tooltip displayed when hovering over tab title
-    wxBitmap bitmap;      // tab's bitmap
+    wxBitmapBundle bitmap;// tab's bitmap
     wxRect rect;          // tab's hit rectangle
     bool active;          // true if the page is currently active
 };
@@ -469,9 +469,9 @@ public:
     /// buttons location (wxLEFT, wxRIGHT, or wxCENTER)
     int location;
     /// button's hover bitmap
-    wxBitmap bitmap;
+    wxBitmapBundle bitmap;
     /// button's disabled bitmap
-    wxBitmap disBitmap;
+    wxBitmapBundle disBitmap;
     /// button's hit rectangle
     wxRect rect;
 };
@@ -539,8 +539,8 @@ public:
     void RemoveButton(int id);
     void AddButton(int id,
                    int location,
-                   const wxBitmap& normalBitmap = wxNullBitmap,
-                   const wxBitmap& disabledBitmap = wxNullBitmap);
+                   const wxBitmapBundle& normalBitmap = wxBitmapBundle(),
+                   const wxBitmapBundle& disabledBitmap = wxBitmapBundle());
 
     size_t GetTabOffset() const;
     void SetTabOffset(size_t offset);