Added SoundSensorTest from exercise 1.

lesson3/SoundSensorTest/src/SoundSensorTest.java

+import lejos.nxt.*;
+/**
+ * A simple sound sensor test program. 
+ */
+public class SoundSensorTest 
+{
+
+   public static void main(String [] args)  
+   throws Exception 
+   {
+       SoundSensor ss = new SoundSensor(SensorPort.S2);
+       
+       LCD.drawString("Sound ", 0, 0);
+       LCD.drawString("Sound lvl ", 0, 2);
+	   
+       while (! Button.ESCAPE.isDown())
+       {
+    	   LCD.drawInt(ss.readValue(),3,13,2);    	   
+       }
+       LCD.clear();
+       LCD.drawString("Program stopped", 0, 0);
+       Thread.sleep(2000);
+   }
+}