ODABAClient :: SayHello - Just say hello to the server ....
The function returns "Hello", when the server is on and NULL otherwise.
Return value:  Value for the variable ( NString & )
Implementation details
NString 
ODABAClient  :: SayHello ( void *testdata, uint32 size )
- testdata - - internal feature (not documented)
- size
 - Size
Size of the instance or string area. 

