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.
Should this just return `Predicate<CharSequence>`?
There should not be anywhere that expects `Predicate<String>` that does not accept `Predicate<CharSequence>`. If there is, we should fix it.