Summary: Implement ClassValue cooperatively with Class like ThreadLocal with Thread.
Reviewed-by: twisti, mduigou

Reviewed-by: smarks

Summary: Test should not use static variables, because they may contain stale values.
Reviewed-by: twisti

Summary: package and class renaming only; delete unused methods and classes; add @since tags; no code changes
Reviewed-by: twisti

Reviewed-by: twisti

Summary: Add ClassValue
Reviewed-by: twisti