Update CrackDetection.java

1) CrackDetection algorithm has been changed to a new one: now it is based on calculating area under the curve in the sideband interval(instead of searching for peak energies in sideband interval)

2)                try {
		  Thread.sleep(8000);  //8 sec
		   } catch (InterruptedException e)
		   {
			// TODO Auto-generated catch block
			e.printStackTrace();
		   }

added to wait 8 seconds in order to give time for other thread "FFT" to complete FFT computation. It is done because synchronization between threads 2 "FFT" and 3 "CrackDetection" is not working now