I am using httrack 4.30. This is having limitations with multithreading and
memory leak issues. As per suggestions I had tried compiling 4.31 beta and
tried to compile my application with this new version. 

Howerver, it seems that this new version does not have backward compatibility
and interfaces are changed.

HTSEXT_API int htswrap_add(httrackp *opt, const char* name, void* fct);
HTSEXT_API unsigned long int htswrap_read(httrackp *opt, const char* name);
HTSEXT_API int htswrap_set_userdef(httrackp *opt, void *userdef);
HTSEXT_API void* htswrap_get_userdef(httrackp *opt);

httrackp *opt is added in some of the apis.

Also hts_uninitialize is removed from the library.

Please let me know, what all changes need to be done to make this application
work with httrack 4.31.

Thanks & regards,
Rajesh