add a special Provides: to all login manager packages

[Kevin Kofler]

Colin Walters wrote:
> Just to give a concrete example, how GDM uses PAM is highly
> nontrivial, involving separate processes because of PAM's
> ill-specified nature among other things.  GDM also interacts with
> various complex cases like smartcards that in turn involve other
> system daemons.  There is quite a bit happening inside GDM/PAM even on
> a default desktop that may not be obvious, such as how gnome-keyring
> saves your password to unlock the keyring.  How gnome-keyring works
> depends on various bits of infrastructure including dbus (this is a
> tricky issue).  NetworkManager in turn depends on gnome-keyring.

Well, display managers which do not support gnome-keyring-pam simply
shouldn't load the module in their PAM configuration, then all you have to
do is to enter your password to unlock the keyring the first time you use
it, nothing catastrophic.

(By the way, we may end up doing that (no longer loading gnome-keyring-pam)
for KDM because some people have issues with gnome-keyring and KDM, the
strange thing is that for others it works perfectly.)

        Kevin Kofler