Add private constructors static classes.

src/de/teamteamteam/spacescooter/sound/SoundSystem.java

@@ -21,6 +21,12 @@ public class SoundSystem {
 	private static SourceDataLine sourceDataLine = null;
 
 
+	/**
+	 * Private constructor, this class will never be instantiated.
+	 */
+	private SoundSystem() {}
+	
+	
 	/**
 	 * Get mixer info and return available sound cards.
 	 */

src/de/teamteamteam/spacescooter/utility/CodeEnvironment.java

@@ -11,6 +11,12 @@ import java.util.zip.ZipInputStream;
 
 public class CodeEnvironment {
 
+	/**
+	 * Private constructor, this class will never be instantiated.
+	 */
+	private CodeEnvironment() {}
+	
+	
 	/**
 	 * Returns true if the program is run out of a jar.
 	 */

src/de/teamteamteam/spacescooter/utility/GameConfig.java

@@ -7,4 +7,10 @@ public class GameConfig {
 	public static int windowWidth;
 	public static int windowHeight;
 	
+	
+	/**
+	 * Private constructor, this class will never be instantiated.
+	 */
+	private GameConfig() {}
+	
 }

src/de/teamteamteam/spacescooter/utility/Loader.java

@@ -17,6 +17,12 @@ public class Loader {
 		Loader.images = new Hashtable<String, BufferedImage>();
 	}
 
+
+	/**
+	 * Private constructor, this class will never be instantiated.
+	 */
+	private Loader() {}
+	
 	
 	/**
 	 * Return the loaded BufferedImage by its filename.