added a change log
Deprecate methods with behavior subsumed by runZoned
removed rerunTests
updated async/future_timeout_test to not assume Zone.ROOT during test run

BUG= https://code.google.com/p/dart/issues/detail?id=13277
R=nweiz@google.com

Review URL: https://codereview.chromium.org//130173010

git-svn-id: https://dart.googlecode.com/svn/branches/bleeding_edge/dart/pkg/unittest@32284 260f80e4-7a28-3924-810f-c04153c831b5