changed 'forfatter' to array and made seperate setter and getter
added to_solr method
made sort fields multiple. Not really a good fix
updated test to multiple authors
views now have 2 authors
Merge branch 'master' of github.com:Det-Kongelige-Bibliotek/DIAS

Conflicts:
	app/controllers/papers_controller.rb
	app/models/paper.rb
	app/views/papers/_form.html.erb
	spec/models/paper_spec.rb