This class will display the content of a directory. It can also give back a data-object that describes the content of a directory, e. g. all files or directories found in that directory. The class aims to function somewhat similar to the UNIX/coreutils program called "ls". The latest version now comes with a test/ directory. The method apply_filter() was added, so now we can filter almost like "ls *foo*" could filter. As of version 1.0.3, showing the Index is optional.