This includes changes from the stim branch, which basically reworked the variable logic to allow cell values to randomise colour properly, as well as introduce a special xyPosition variable to pass a 2 element vector to set both X and Y position in one call, which optimises the number of variables needed for a range of behavioural paradigms. We also added in an apparentMotionStimulus for some pilot work. Also we can now have multiple fixation targets simultaneously updated dynamically by the state machine.