[product: zaphod][project: zaphod-v0.3]: Execute shell commands on localhost.

SYNOPSIS
[new]m42/cmd.py: Shell command execution utilities.
[new]m42/test/test_cmd.py: Tests for cmd.py.

DETAILS
cmd.py provides a simplified interface for executing shell commands. Over
time it is intended that all localhost shellcommand execution capabilites
will reside in this module. Right not they are scattered across the code
base.