GUI skins: The loader now recovers cleanly from errors and displays a message that says what's the problem in the image.

git-svn-id: svn://pulkomandy.tk/GrafX2/trunk@881 416bcca6-2ee7-4201-b75f-2eb2f807beb1

windows.h

@@ -70,6 +70,7 @@ void Print_counter(short x,short y,const char * str,byte text_color,byte backgro
 
 byte Confirmation_box(char * message);
 void Warning_message(char * message);
+void Verbose_error_message(char * message);
 
 void Display_image_limits(void);
 void Display_all_screen(void);