Better animation out
Automatically generate sections on upload

When a student list is uploaded, sections are automatically created or
deleted as needed.

Admins are assigned a fake section with the name `A9`
Fixes #73
Fixes #86

It now wont let you start the test/start grading if it's too late. Also
shows a schedule with the next three exams on the start page.
Fixes #87

Caused because private variables aren't serializable and because
student references a section object which had private variables.
Timer fix

Made a change so that if the time till end is less then time till late,
it only shows the time till end.
Merge branch 'issues'