trackers and trackables should be namespaceable

[ojbucao]

currently there's no way to namespace trackers and trackables because the methods that take in class names do not expect namespacing. There should be a way to use namespaces as this will help clear up the specs. Test classes for trackers and trackables interfere with each other if they have the same name.

[dblock]

@ojbucao Resurrecting this, do you remember what the issue looked like in code?