Primitive logic to navigate from step to step; created 2 subvis

Created "main" vi.
Basic front panel organization: tabbed view for setting and shear;
power, proceed, preceed, and start over buttons.
Basic logic to navigate between steps and keep track of current state.

Created shell sub-vis: BallShear_DependencyCheck (check peripherals for
shut down / start up) and BallShear_PackageCheck (check for correct
placement of package at beginning of shear).