Updates pull request from Roman Tsypuk to convert the build system from

ant to gradle.  Removes linux and windows application launch scripts and
produces an executable jar with all resources included.

src/main/java/io/github/dsheirer/buffer/CircularBuffer.java

@@ -0,0 +1,94 @@
+package io.github.dsheirer.buffer;
+
+import io.github.dsheirer.sample.Listener;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.List;
+
+public class CircularBuffer<T> implements Listener<T>
+{
+	private ArrayList<T> mElements;
+	private Listener<T> mListener;
+	private int mPointer;
+	private int mSize;
+
+
+	/**
+	 * Circular Buffer - stores elements in an array list.  Once the buffer is
+	 * full, new samples replace older samples and older samples are broadcast
+	 * to an optional listener.
+	 * 
+	 * @param size - size of buffer
+	 */
+	public CircularBuffer( int size )
+	{
+		mSize = size;
+		mElements = new ArrayList<T>();
+	}
+
+	/**
+	 * Returns the element stored at index.  Note: the index argument refers to
+	 * the internal storage index and does not indicate a temporal relationship
+	 * among elements.  For example, if you get indexes 1, 2, and 3, you may be
+	 * getting ( oldest - 1, oldest, newest ) elements, if the internal pointer
+	 * is currently pointing to and will insert the next element at index 4.
+	 * 
+	 * @param index - element index
+	 * 
+	 * @return element or null
+	 */
+	public T get( int index )
+	{
+		if( index < mElements.size() )
+		{
+			return mElements.get( index );
+		}
+		
+		return null;
+	}
+	
+	public int getSize()
+	{
+		return mSize;
+	}
+	
+	public List<T> getElements()
+	{
+		return Collections.unmodifiableList( mElements );
+	}
+	
+	@Override
+	public void receive( T element )
+	{
+		T previous = null;
+		
+		if( mElements.size() > mPointer )
+		{
+			previous = mElements.get( mPointer );
+			
+			mElements.set( mPointer, element );
+		}
+		else
+		{
+			mElements.add( element );
+		}
+		
+		mPointer++;
+		
+		if( mPointer >= mSize )
+		{
+			mPointer = 0;
+		}
+		
+		if( previous != null && mListener != null )
+		{
+			mListener.receive( previous );
+		}
+	}
+
+	public void setListener( Listener<T> listener )
+	{
+		mListener = listener;
+	}
+}