added script to demonstrate how to trigger the otpacon through the serial port.
added script to display a white square in the corner of the screen to trigger the photosensory, which in turn triggers the start of stimulus presentation.
Updated script for making stim files for pilot 1. Removed randomisation, and repeats of 'sham' stimulus since these things will be handled in the adaptive staircase. This now produces an optacon protocol file with each unique stimulus as a block in the protocol. Staircase procedures can call stimuli by block.