Authentication UI for accounts-sso

https://code.google.com/p/accounts-sso/

This is a authentication UI for the Accounts and Single Sign-On
framework. It includes a D-Bus service. When queryDialog() is 
called the service will, if needed, show the user a Elementary 
(EFL) authentication dialog and return the results of this
authentication when user is ready.

The dialog is a minimal implementation: it does not try to be fancy,
and has only been 'designed' to the point where all the supported
options are somewhat available in the UI. Proper user interaction
design will likely result in a re-implementation of sso-ui-dialog.

This implementation is currently untested with any real sso
daemon, and the D-Bus API is largely undocumented, so interoperability
fixes are likely to be needed: As an example, the D-Bus names and paths
are mostly made up. It does include a small test suite and
tools to trigger the dialog for manual testing.
