New Features: 1. Added function "run" to CLI class to run command once and exit (more traditional CLI framework capability).
0.0.3
New Features: 1. Added an option to expand asterisk into file names just like shell does. 2. Added "tee" and "sed" to default allowed unix commands. 3. Added a hidden CLI class method "list_shell_commands".
Bug Fixes: 1. Fixed a bug with appendable argument that happens when no argument is provided.