ProcGUI: refactored how the mode button is handled
ProcGUI: capitalized Classes.  Refector mode button.
ProcGUI: rename files
ProcGUI: rename files
ProcGUI: added adjustable vert scale button

Vertical scale of montage plot (which also controls the vertical scale
of the FFT plot and the color scale of the head plot) can now be changed
via a button on the GUI.
ProcGUI: log/linear vertical scale on FFT and Head
ProcGUI: renamed "gui mode" to "gui page"
ProcGUI: refectored main draw() to make it easier to understand
ProcGUI: adjusted redrawnow. chasing startButton problem
ProcGUI: fixed redrawnow so that stop/start button looks right
ProcGUI: added delay to playback data in real time
ProcGUI: added multiple filtering options
ProcGUI: playback: fixed fast play.  now wraps around

Fixed bug where, if you hit stop, waited, then start, the speed of
playback would be fast until it caught up with the amount of time that
past while it was stopped.  I fixed this.  Also, when it hits the end of
the playback file, it now automatically starts back at the beginning
again....it now will loop continuously.
ProcGUI: refactored getData.  still stutters on home PC
ProcGUI: added comments.  Tested Proc 2.1.1.  Still need to test Serial.

Tested on Processing 2.1.1 64-bit.  Only tested playback from file.
Stuttering is less bad.  Did not test Serial.
ProcGUI: channel buttons now affect playback data
ProcGUI: added smoothing to headPlot. added button
ProcGUI: fixed headplot so it doesn't update when stopped
ProcGUI: added Bias Auto/Ref Button
ADS1299Manager: can now toggle bias mode

Toggle bias generation between "auto" (each channel affects the bias as
it is activated or deactivated) and "fixed" (the bias is just the
midpoint between the voltage rails...it is not connected to the channels
at all).