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.
Also we could be upgrading a cluster with failed nodes to fix a rebind bug, can we force new instances to stay in HOT_STANDBY?