Minor changes to Communication Examples

Added a note to the included Processing sketches about replacing
println(Serial.list()) with Serial.printArray() if using Processing 2.1
or later

build/shared/examples/04.Communication/Graph/Graph.ino

@@ -63,13 +63,17 @@ void loop() {
  size(400, 300);        
  
  // List all the available serial ports
+ // if using Processing 2.1 or later, use Serial.printArray()
  println(Serial.list());
+ 
  // I know that the first port in the serial list on my mac
  // is always my  Arduino, so I open Serial.list()[0].
  // Open whatever port is the one you're using.
  myPort = new Serial(this, Serial.list()[0], 9600);
+ 
  // don't generate a serialEvent() unless you get a newline character:
  myPort.bufferUntil('\n');
+ 
  // set inital background:
  background(0);
  }