Region tree

This is a pretty sweet PR for many reasons. In a nutshell, this guy updates the region inspector so that it ships a region tree with just view cids. It no longer ships the fully serialized views. We can do this update because we started shipping serialized views in an earlier release and we already have a UI viewCollection. Building and shipping a much smaller region tree is a huge perf win.

Equally importantly, this PR has two code quality wins:

1) the region inspector was refactored to live inside a closure. `(function() {}())` 
  This seems obvious now, but most of the agent modules are defined in the agent context and will be encapsulated in closures going forward.

2) the region inspector now has test coverage. this is also one of those obvious wins, but getting that really helped the iteration and will help going forward immensely.