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.
Regarding the sieve_test:
Manuel fixed some problems in these test and I think I have these changes in this branch. 
I just ran the test in riak_test and it passed. I also ran them in command line and it also completed. For example, if I give 20 as the input(maximum), it returns [2,3,5,7,11,13,17,19].