User interface for Node (department/faculty) admins

[espenak]

Node admins are the admins who have access to a huge amount of subjects. They need a user interface where they can browse their departments (including subjects, semesters, assignments, students, ...). Most of this is already covered by the new subject admin UI (version 1.2), so we only need a couple of new views, and some shortcuts:

• A frontpage with a subview where they can browse all their nodes (departments/faculties).
• Links from the frontpage that gives them easy access to their most common actions. So far we think these actions are:
  • Extend a deadline
  • View all information about a single student. We may leave this for later if it is to much work.
• Search. Similar to the search feature in the currently stable version, but faster, better organized and a less ugly UI.
• Guides for the most common actions (like the "create new assignment guide" in the subjectadmin UI)

See also: #307

[espenak]

I am closing this issue, but making the guides into a separate issue. The search will be implemented with #308.