Update "Simpler" Processing GUI.  Adds spectrogram and alpha detection

Added spectrogram and (visual) alpha detection to the "Simpler" Processing GUI.  

  * Can toggle between time-domain montage and the spectrogram.  Title of spectrogram shows which channel is being plotted in the spectrogram.

  * The Alpha "Detection" algorithm just looks for a peak in the right frequency band that is a certain dB higher than the background EEG acitivity.  A detection is indicuated visually.  Eventually, it would be good if the GUI actually made noise when it detected alpha.  If it made noise, you'd know that you were making Alpha, even when your eyes are closed.