Access to the web based updater has to be protected.

Idea:
Store some user password hash in a file within the updater and display a login form to the user when accessing the updater.

To think about:
smooth integration with owncloud core. we want the admin in the admin section to simply click a link
which opens the updater in a new tab/window.
In an ideal world no login form is displayed since we already know that the admin is authorized.