Rhs2116 Stimulus Sequence Dialog - Plot pulses with a red overlay to highlight them

[bparks13]

After plotting the stimulus sequence waveform, plot an overlay where every pulse is highlighted with a red line to emphasize it. This is especially useful for relatively small pulses, which can be hard to visualize when fully zoomed out.

This will probably be easiest to do by building an array or list that contains the XY coordinates of the pulses as they are added to the full waveform, and then plotting them in a separate method. Need to make sure that the Z-order is correct so that the red is on top of the blue lines.