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/spectrum/menu/SmoothingItem.java

@@ -0,0 +1,75 @@
+package io.github.dsheirer.spectrum.menu;
+
+import io.github.dsheirer.spectrum.SpectralDisplayAdjuster;
+import io.github.dsheirer.dsp.filter.smoothing.SmoothingFilter;
+
+import javax.swing.*;
+import javax.swing.event.ChangeEvent;
+import javax.swing.event.ChangeListener;
+import java.awt.event.MouseEvent;
+import java.awt.event.MouseListener;
+import java.util.Hashtable;
+
+public class SmoothingItem extends JSlider implements ChangeListener
+{
+    private static final long serialVersionUID = 1L;
+
+    private SpectralDisplayAdjuster mAdjuster;
+    private int mDefaultValue;
+    
+    public SmoothingItem( SpectralDisplayAdjuster adjuster, int defaultValue )
+    {
+    	super( JSlider.HORIZONTAL, 
+    		   SmoothingFilter.SMOOTHING_MINIMUM, 
+    		   SmoothingFilter.SMOOTHING_MAXIMUM, 
+    		   adjuster.getSmoothing() );
+    	
+    	mDefaultValue = defaultValue;
+    	mAdjuster = adjuster;
+    	
+    	setSnapToTicks( true );
+    	setMajorTickSpacing( 6 );
+    	setMinorTickSpacing( 2 );
+    	setPaintTicks( true );
+    	setPaintLabels( true );
+    	
+    	Hashtable<Integer,JLabel> labels = new Hashtable<>();
+    	labels.put( new Integer( 3 ), new JLabel( "3" ) );
+    	labels.put( new Integer( 9 ), new JLabel( "9" ) );
+    	labels.put( new Integer( 15 ), new JLabel( "15" ) );
+    	labels.put( new Integer( 21 ), new JLabel( "21" ) );
+    	labels.put( new Integer( 27 ), new JLabel( "27" ) );
+    	
+    	setLabelTable( labels );
+    	
+    	addChangeListener( this );
+
+    	addMouseListener( new MouseListener()
+		{
+			@Override
+			public void mouseClicked( MouseEvent event )
+			{
+				if( event.getClickCount() == 2 )
+				{
+					SmoothingItem.this.setValue( mDefaultValue );
+				}
+			}
+			
+			public void mouseReleased( MouseEvent arg0 ) {}
+			public void mousePressed( MouseEvent arg0 ) {}
+			public void mouseExited( MouseEvent arg0 ) {}
+			public void mouseEntered( MouseEvent arg0 ) {}
+		} );
+    }
+
+	@Override
+    public void stateChanged( ChangeEvent event )
+    {
+		int value = ((JSlider)event.getSource()).getValue();
+
+		if( value % 2 == 1 )
+		{
+			mAdjuster.setSmoothing( value );
+		}
+    }
+}