gnome-keyring Initial whack at dbus interfaces

[Stef Walter <stef-list memberwebs com>]

Attached are my initial try at some dbus interfaces for secret storage.
Hopefully we can implement something like this in gnome-keyring.

Some comments:
 * Idea for objects laid out like so:
   /org/freedesktop/secrets   (Object representing the whole service)
   /org/freedesktop/secrets/collections/xxxx (represents a keyring)
   /org/freedesktop/secrets/default (easy access to default keyring)
   /org/freedesktop/secrets/collections/xxxx/yyy (item in a keyring)

 * These are designed to generic enough be implemented not just by
   gnome-keyring.

 * These are designed for applications. Some management functionality
   will probably be on other interfaces on the same dbus objects.
   eg: change keyring password, set idle timeouts, item mtime/ctime

 * Concept of ACLs has moved to the collection level. That is an
   application with private secret storage would create a collection
   (keyring) with restricted access rights.

 * The 'Negotiate' method establishes cipher and does key agreement,
   like Michael did some work on.

 * Secrets are transferred as a pair if strings, the first contains
   cipher specific parameters (ie: IV etc.)

This is just an initial rough draft. Any comments? Am I looking at any
of this in the right way? Is there anyone else we should involve in this
discussion?

Cheers,

Stef