Added valgrind strategy to courses.json for clients to use
Show extra student files in submitted files list
Merge pull request #183 from jamox/source_file_list_includes_extra_student_files

Show extra student files in submitted files list
CourseRefresher: delete old cache after commit, not before.
Merge pull request #184 from testmycode/delete-old-cache-after-commit

CourseRefresher: delete old cache after commit, not before.