Brooklyn node and cluster upgrade

Merges #266 (cluster upgrade) with work I've been doing on node upgrade.

Builds on #260 so please ensure that is merged first.

Needs further testing (by me at this point) but wanted to push it in case @neykov you have comments, especially on the last commit.
great idea.  i have added 3727b07b9d8f46cd629c5ec9e992bf67db7c54a0:

    refactor recent changes so that Repeater tasks are in Tasks and EntityTasks reuse cleaned up DependentCongifuration,
    with DependentConfiguration now relying on an internal class and:
    * checking for unmanaged (and now this is the default)
    * supporting a timeout
    * ensuring that all values put into the subscription queue are read (previously it could miss a value if subscriptions were updated twice in succession)