Ensure that the home screen is loaded automatically

Ensure that the home screen is loaded automatically

Now, when the application starts, only a blank page is shown. The home
screen (summary graphs for all users) shows only after somebody logs
in and out. With this change, the home screen is loaded automatically
on the first start or on manual page reload.

Together with this change, we split the home and user screens to
separate templates (previously the home screen was the user screen
with name unset). Hopefully, this change makes the UI logic a bit
easier to follow.