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.
Persistence options need not be specified  at the command line for it to be active. The main method could be activating it instead. The only way to find out what's the persistence mode is through the REST API.