Completed gnome-keyring-manager functionality in seahorse

[Stef Walter <stef memberwebs com>]

I've added all the remaining functionality of gnome-keyring-manager to
seahorse. Most of it is apparent in the preferences. Please do bang away
at it and see if there's anything that I screwed up on.

You'll notice that I put the 'Passwords' tab first in the preferences. I
think it should be that way in the main 'Passwords and Encryption Keys'
window.

Sad as it is (with respect to our roots), the passwords functionality is
what most people will end up using seahorse for.

We may also want to move our desktop entries into the Preferences menu
of GNOME. I think it makes the most sense there. In my opinion it's a
tool used less frequently for managing an aspect of the user's
configuration.

Cheers,
Stef Walter