frontend.views.upload: uploaded flights are private by default

Force users to confirm their upload prior to publishing the uploaded flights.
templates/upload/*: show status label in tab bar
templates/upload/details: remove "Show" link

Don't let users belief their flights have been published already
just becase they can click the "Show" button...
templates/upload/result: show vertical tabs only if more than one flight was uploaded
frontend.views.upload: finally redirect to a list of uploaded flights
frontend.views.upload: trigger delayed analysis after publishing