manager: close up timed login race

Previously we would emit the timed-login-requested signal after the
client connects, which might be before it was listening for the
signal.

Now we only emit the signal in direct response to a GetTimedLoginDetails
call, which we make implicitly when the appropiate proxy interface is
set up.

https://bugzilla.gnome.org/show_bug.cgi?id=680348
Updated Swedish translation