1. Name change: Sensor2Serial >> Sensor2Serial_Esplora

2. Simplified Sensor2Serial_Esplora: numerical data sent out
   has the natural range, e.g., 0..1023 for the linear potentiometer,
   -512..512 for joystickX.  It is up to the receiving program
   to interpret these values.

3. Modified Seurat.pde to account for the changes in (2).  Added
   a new variable INTIAL_RADIUS, which is set to 24, so that
   MAXRADIUS, initialized to 240, can play its intended role.