Supervisor modes

I changed operations so that it can be applied to replicated nodes, including bind, read, next, wait_needed, is_det, declare. There are still two operations 'fetch'  and 'reply_fetch' to be done. They are used to fetch values when a dataflow variable is bound to another.
You realize that this introduces a pretty easy deadlock situation, right?  If the preflist generated by the declare FSM contains the vnode this call is made from, the system deadlocks.