Improve interactive CLI experience by implementing tab-completion and iteration through command history via pressing up/down keys.

[ns-echen]

For a demonstration of current CLI behavior, issue the command: lsi -s [filter]. When the user attempts to specify the SSH identify file argument by typing "i [path to keyfile]" at the prompt, neither the tab-completion nor the history features are available.
These could potentially be implemented with the Python readline and rlcompleter modules.