Merge pull request #11029 from owncloud/fix-share-download

apps/files_sharing/appinfo/routes.php

apps/files_sharing/application.php

apps/files_sharing/js/public.js

apps/files_sharing/lib/controllers/sharecontroller.php

apps/files_sharing/lib/helper.php

apps/files_sharing/lib/middleware/sharingcheckmiddleware.php

apps/files_sharing/public.php

apps/files_sharing/templates/authenticate.php

apps/files_sharing/templates/public.php

apps/files_sharing/tests/controller/sharecontroller.php

...files_sharing/tests/middleware/sharingcheckmiddleware.php

apps/files_sharing/tests/testcase.php

core/routes.php

core/share/controller.php