* Installing accounts .provider and .service files directly
into /usr/share/accounts is difficult. SyncEvolution doesn't
know whether it needs to install for UOA or gSSO (they are
slightly different) and installing "google.provider" may
conflict with other packages.
It would be good if it was possible to include several sets of authentication settings in
.service files for different SSO backends (as opposed to just one set as is the case
currently). I'm not a libaccounts expert, but I think
ag_account_service_get_auth_data() could return the settings for the platform's
'default' sso (and identify what it is), and there would be additional methods for
enumerating and retrieving auth settings that would include also their SSO identifier.