OS X password hash support

[GoogleCodeExporter]

It would be nice to support MacOS X's password hash format. 

http://www.dribin.org/dave/blog/archives/2006/04/28/os_x_passwords_2/ contains 
a good walkthrough of it's history for OS X 10.0 - 10.4. 

Things left to do:

1. Find source of info for remaining OS X releases, figure out what things have 
changed.

2. Work out the best interface for handling a complex multi-digest hash string 
like this.

3. Given the complexity, need to gather a BUNCH of test vectors for known 
passwords (ascii and unicode), under various security configurations, to ensure 
the walkthrough above is actually accurate. This is currently the primary 
blocker for this issue. 

Original issue reported on code.google.com by [email protected] on 27 Jun 2012 at 10:13