Use file coordinators to lock down access to our cloud files and handle conflict versions.

[IMPROVED]  More reliable method for getting the latest StoreUUID:
                - Use file coordinators to make sure we have the latest StoreUUID.
                - Use file coordinators to lock read/write access to our files down.
                - Use conflict detection and resolution to handle StoreUUID changes for offline peers.
                    - The earliest conflict version wins, as a result a peer that starts offline and comes online reverts to the existing cloud store instead of making it unavailable for the other peers.
                    - The latest corruption version wins, older corruption versions may no longer be valid but can still be detected again.