This command adds a long long integer
to the specified packet. Typically long long integers are 8 bytes in
size and range from -9,223,372,036,854,775,808 to +9,223,372,036,854,775,807.
The data will be added starting at the cursor position and the cursor will be moved forward by the size of the data added.
long long int Packet: This is the packet that the command should use.
long long int: This is the data to be added.
0 if no error occurred.
-1 if an error occurred.
C++