id_generator moved to clean_sync
onBeforeAdded, onBeforeRemoved changed to onBeforeAdd, onBeforeRemove
Add hop runner.
renamed onBeforeNotify, expectAsync in tests in Timer.run()
Merge pull request #16 from cleandart/origin/separateDataChangeListeners

Origin/separate data change listeners
Merge branch 'master' into feature/notification_mixin

Conflicts:
	lib/src/data_collection.dart
	test/id_generator_test.dart