Summary: Change the finalize method of PKCS11 class to be protected.
Reviewed-by: xuelei

Summary: Use @Native annotation to mark constants interested by native codes
Reviewed-by: alanb, anthony, prr

Reviewed-by: ohair, ohrstrom, ihse

Summary: Enhanced the PKCS11 Digest implementation to support cloning
Reviewed-by: vinnie

Reviewed-by: darcy, weijun