renamed extention to extension, also now only showing lowercase

apps/files_archive/lib/tar.php

apps/files_encryption/lib/proxy.php

apps/files_sharing/get.php

apps/media/js/loader.js

apps/media/js/music.js

apps/media/lib_scanner.php

core/js/js.js

files/css/files.css

files/index.php

files/js/filelist.js

files/templates/part.list.php

lib/filestorage/common.php

lib/helper.php

lib/mimetypes.list.php

lib/template.php