Modified interpreter to stop running when program halts on hardware. Previously it was just running the same program over again. Under Cygwin, the program is limited to 1000 steps before halting. This prevents a program that never quits, and therefore grows the log file, to be forced to stop.
Modified the valve5.def program to do real movement with the motor.
Parser was not recognizing negative numbers. This became immediately apparent when trying to move the motor backwards. Fixed in valve.y.
The current program moves the motor 10 small steps counter-clockwise then 1 big step back clockwise to where it started.