Various unsafe code in nlp_engine.cpp

[dhdaines]

Widespread use of fixed-size buffers on the stack as strings is quite unsafe (too many examples to list but everywhere MAXPATH or MAXSTR is used).

Consider using _stprintf_s on Windows or snprintf on Unix, or using std::string (since it is being used elsewhere).

Also the ownership of _TCHAR * arguments pased to the API functions is unclear, it appears that they take ownership (and so these strings should not ever be deallocated by the caller).

Again consider using std::string since this is a C++ API. Otherwise mark them as const and copy the contents.