Added class typedef.

blitz.mod/blitz_types.h

@@ -24,6 +24,7 @@ typedef struct BBInterfaceTable BBInterfaceTable;
 typedef struct BBInterface BBInterface;
 typedef struct BBInterfaceOffsets BBInterfaceOffsets;
 typedef struct BBEnum BBEnum;
+typedef struct BBClass_String BBClass_String;
 
 typedef unsigned char	BBBYTE;
 typedef unsigned short	BBSHORT;