Cleans up __new__ method of Message to correct semantics
Renames MTS50.py to mts50, fixes __init__ error in mts50.py
Adds close() method to Controller
Fixes some pyflake warnings, tweaks status decoding based on reality
Adds timing of move intervals from command issue to full stop
Removes extraneous whitespace
Make utility scripts instantiate a MTS50 object
Adds raw option to Controller.velocity_parameters

This aids in figuring out the actual scaling relationship between reported
values and real values of position, velocity, and acceleration
Updates scaling constants in MTS50 so we get the same numbers as APT User