Resolve "Wiki modernisieren"

app/controllers/course/wiki.php

app/controllers/jsupdater.php

app/controllers/public_courses.php

app/controllers/studip_controller.php

app/controllers/wiki.php

app/routes/Wiki.php

app/views/course/wiki/admin.php

app/views/course/wiki/allpages.php

app/views/course/wiki/blame.php

app/views/course/wiki/diff.php

app/views/course/wiki/edit.php

app/views/course/wiki/history.php

app/views/course/wiki/import.php

app/views/course/wiki/newpages.php

app/views/course/wiki/page.php

app/views/course/wiki/search.php

app/views/course/wiki/version.php

app/views/course/wiki/versioncompare.php

app/views/course/wiki/versiondiff.php

app/views/wiki/change_courseperms.php