New scope checker feature.

The implementation is somewhat complex; if you're reading this please consider reading through the code to find some mistakes!

I'm considering moving this out to be a proper extension; for now it'll live in util.

git-svn-id: https://google-guice.googlecode.com/svn/trunk@1049 d779f126-a31b-0410-b53b-1d3aecad763e
8 files changed