make dartdoc and editor happy
make dartdoc and editor happy

added type to Logger.level setter
added type to Logger.root

Review URL: https://codereview.chromium.org//12316126
Patch from Kevin Moore <kevmoo@j832.com>.

git-svn-id: 29b42837285a5fdcb6c8ad0409bff8538fc60ed2@19186 260f80e4-7a28-3924-810f-c04153c831b5

dart-lang/logging,astashov/logging