OperationSynchronize -> OperatorSynchronize
OperatorSerialize
not quite functional ... and slow
Functional now ... it seems.
Migrate Merge from Synchronize to Serialize
Experimenting with different implementations and performance
Clarify names during testing
Unit tests for each
Unlock in finally block
queue and lock implementation
SerializedObserver and SerializedSubscriber

Using the "queue and lock" implementation which won our performance and production testing.
Synchronize -> Serialize

- migrate all usage to Serialized instead of Synchronized
- remove implementations of SerializedObserver that lost the competition (performance and testing in production)