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

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.
