Components without command crash

[cbravo135]

Components crash if they don't initialize the command member since the default in the Component class is None.
One example of this is the MoveFile component in tools.py.
A workaround I am currently using is to change the default init of command in Component to '' instead of None.

[JeremyMcCormick]

A workaround I am currently using is to change the default init of command in Component to '' instead of None.

Without looking at it in much detail, I would think that small change could just be made in master for now if it fixes the issues with crashing.