auth-source.el request: NS port needs Mac OS X keychain functions

[Ted Zlatanov]

I'd like to add an auth-source.el backend that supports the Mac OS X
keychain.  The NS port needs the Mac OS X keychain functions:

http://developer.apple.com/library/mac/#documentation/Security/Conceptual/keychainServConcepts/03tasks/tasks.html

in order to be better integrated with the OS-level security in Mac OS X,
especially for users that want to share passwords between other Mac OS X
applications and Emacs.

Can we please get SecKeychainItemModifyAttributesAndData(),
SecKeychainAddInternetPassword(), SecKeychainFindInternetPassword(),
SecKeychainAddGenericPassword(), and SecKeychainFindGenericPassword()
added?  I don't know that platform well so it would take me a while; it
seems like a fairly simple task for someone more expert (and there's
full source code on that page).

Thanks
Ted