Cut code up into smaller chunks, adding files

  DrawHelpers.pde Globals.pde Serial.pde Setup.pde

Removed some dead code.
Enabled experimental mode --- it seems to work well!

Used its diagnostic messages to remove more dead code.
Modified Slider.pde so that current value is indicated by a shorter
red bar superimposed on the main blue bar.
Delete manageColorWheel1,2 in favor of a method, setColorOfBox,
 in class ColorWheel.
Eliminated manageControl in favor of method react in Control class.
Chaanged updateFrames to setParticleTypeInframes.
Added a catpion to Sliders.
Added new bank of controls, operated by the key 'c' and the
boolean variable controlsActive2. At the present, there is just
one control in this: frameAlpha.
Added class Widget.  Now Slider and Control inherit fromit.
ColorWheel now inherits from Widget.  Issue with max and min Value
sliders fixed.
Fixed: now only one set of controls can be active at a time.
Added read method to Widgets: return x-value of mouse in local coordinates.
Put controls in black strip at bottom --- can't hide them.