Update part subscribers as message

- [ ] @EEE3 please test

_notes_
 - update app.config file. need to add .CollectStat metric.  also update RestAfter... values
 - messages are mapped to subscribers on publish
 - new partitions don't start with subscribers registered.  a message is published to the hub to register them.  messages won't be mapped to subscribers until they are published to the partition.  when the hub registers the subscribers, it will map any unmapped messages and all messages from that point will be registered

- [x] to test
 - [x] part-add with /prepNow
 - [x] part-add without /prepNow
 - [x] part-add while hub is running
 - [x] part-add and publish messages before hub is running
 - [x] messages are mapped to subscriber on publish
 - [x] when partitions are added, message are eventually mapped to subscribers and processed