Fix issue 496: Some animated GIF images don't load well. Also fixed the handling of transparency in preview (fileselector) and loading anim GIF as a brush loads first frame.

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@1969 416bcca6-2ee7-4201-b75f-2eb2f807beb1

src/loadsave.h

@@ -207,6 +207,8 @@ void Pre_load(T_IO_Context *context, short width, short height, long file_size,
 void Palette_loaded(T_IO_Context *context);
 /// Generic cleanup done on end of loading (ex: color-conversion from the temporary 24b buffer)
 //void Post_load(T_IO_Context *context);
+/// Fill the entire current layer/frame of an image being loaded with a color.
+void Fill_canvas(T_IO_Context *context, byte color);
 
 /// Query the color of a pixel (to save)
 byte Get_pixel(T_IO_Context *context, short x, short y);