QSafeBitmapResourceReader does not check if the bitmap is already loaded

There is no check in the resource reader if the bitmap is already loaded or not.
The file reader class has the proper checking. The data overhead is not big because the resource reader does not load the data but just sets the pointer to the data section where the bitmap data is located.
The end result is that Constraints::MAX_AMOUNT_OF_BITMAPS get overrun when you are having the case where that same bitmap files and used in the several item transitions).