Large Stage Movement

[AdvancedImagingUTSW]

When we start the software, the user must do hit the set start position/focus and set end position/focus buttons, or else the stage will make a large movement when they start to acquire a Z-Stack. It would be good to prevent this from happening.

If those values are altered (e.g., in the spin box), presumably it should just operate relative to the current position for X, Y, and Theta.