3 headsets one sketch

This processing sketch needs to be in a folder of its own name and
contain a folder called "data" that includes three text files:
data_Serial_1.txt, data_Serial_2.txt, and data_Serial_3.txt.  The
technique to read from multiple serial ports simultaneously comes from
Tom Igoe's example here: http://www.tigoe.com/pcomp/code/misc/167/