Barrier released at Server_Body right after its been used and will never be used again
Data_Thread data set allocated in special function

before, this data set was malloced in Start_Data_Thread
Start_Data_Thread is in charge of allocated array for thread PID and
barrier
removed barrier from data_thread_args, replaced by pt_sync
comments in Data_Thread.c
DataBuffer checked in Start_Data_Thread
check Data_Thread->data_threads == NULL
added example file to Example1