Add fiji icon in the resources

Fixed it for handling the situation that fiji.sc site does not provide Fiji-icon.png properly.

src/main/java/bdv/ij/BigDataBrowserPlugIn.java

@@ -44,7 +44,7 @@ public class BigDataBrowserPlugIn implements PlugIn
 		BufferedImage image = null;
 		try
 		{
-			image = ImageIO.read( new URL( "http://fiji.sc/_images/a/ae/Fiji-icon.png" ) );
+			image = ImageIO.read( getClass().getResourceAsStream( "/fiji.png" ) );
 		}
 		catch ( final IOException e )
 		{