Created a new Pair class so that it can run on a non-Mac machine

Basic File I/O is functional
Fixed deadlocking issue when 1 server is down. The error handling for a failed server needed an additional check for "replicate" message. The release mutex was never being called.

This exposes another problem where the threads are not getting notified properly if multiple requests are in the queue.
Adding the code for server sleep back in
Put the serverSleep counter decrement within critical section. For some reason, it was not getting called properly.