The Tor Browser / file revision

 This Cryptoki module provides acces to certs and keys stored in

 Macintosh key Ring.

 - It does not yet export PKCS #12 keys. To get this to work should be 

   implemented using exporting the key object in PKCS #8 wrapped format.

   PSM work needs to happen before this can be completed.

 - It does not import or export CA Root trust from the mac keychain.

 - It does not handle S/MIME objects (pkcs #7 in mac keychain terms?).

 - The AuthRoots don't show up on the default list.

 - Only RSA keys are supported currently.

 There are a number of things that have not been tested that other PKCS #11

 apps may need:

 - reading Modulus and Public Exponents from private keys and public keys.

 - storing public keys.

 - setting attributes other than CKA_ID and CKA_LABEL.

 Other TODOs:

 - Check for and plug memory leaks.

 - Need to map mac errors into something more intellegible than 

   CKR_GENERAL_ERROR.