[fix:test] These changes address test stability on underperforming platforms.
[fix:windows] The Local Cluster manager didn't work on windows since it used the file system line separator in the zookeeper directory structor.
[fix] There was a slight chance that if the cluster manager failed, then worked, then failed in a short period of time, then a pre-instantiation state change might be missed.
[fix] When batching messages, if the first message in a batch is bigger than the mtu, then it wasn't being sent until the next message comes in (or the message timeout). It now sends it immediately.