* Add tracker types and tests
* Modify ResourceEventHandler interface's OnAdd member
* Add additional ResourceEventHandlerDetailedFuncs struct
* Fix SharedInformer to let users track HasSynced for their handlers
* Fix in-tree controllers which weren't computing HasSynced correctly
* Deprecate the cache.Pop function
Kubernetes-commit: 8100efc7b3122ad119ee8fa4bbbedef3b90f2e0d
