Linux support for Graffik

These patches enable Linux support for Graffik.  I've tested them on Ubuntu 12.04 LTS (64-bit) and Ubuntu 13.04 (64-bit).  Nanomoco stepper motor control works in both Script and Film modes, and the GUI appears to be functional.  
I've done my best to ensure the changes will not impact users of other platforms, but testing should be done to ensure the commits do not cause problems for Windows or Mac users.