test name should be available to setup and teardown

By making the test name part of the context in the setup and teardown method names its possible to have slight variations on these methods. It would also allow to easily hook up recording mechanisms for mocking, etc.

Start by tracing how nodeunit discovers tests and invokes setup and teardown in its JavaScript source. Determine how the test name can be exposed in that context, then verify that setup and teardown can vary by test name and that existing behavior remains intact.

Written by the indexing model from the issue text.