Use CachingImageList.GetImageIndex for bitmaps that resides on FS, let wx.ImageList.Add deal with the rest (memory bitmaps)

gui/cachingImageList.py

@@ -25,7 +25,7 @@ class CachingImageList(wx.ImageList):
         wx.ImageList.__init__(self, width, height)
         self.map = {}
 
-    def Add(self, *loaderArgs):
+    def GetImageIndex(self, *loaderArgs):
         id = self.map.get(loaderArgs)
         if id is None:
             bitmap = bitmapLoader.getBitmap(*loaderArgs)

gui/marketBrowser.py

@@ -139,7 +139,7 @@ class MarketTree(wx.TreeCtrl):
         if iconFile is None:
             return -1
 
-        return self.imageList.Add(iconFile, "pack")
+        return self.imageList.GetImageIndex(iconFile, "pack")
 
     def expandLookup(self, event):
         root = event.Item