merge from head
Merge branch 'master' of https://github.com/NZOI/nztrain

Changed stuff to make it work on my machine.

Conflicts:
	app/views/layouts/application.html.erb
Changed association between test cases and test sets

now it is a :has_many through a test_case_relation class.
Merge branch 'master' of https://github.com/NZOI/nztrain