Java 6 compatibility

System.lineSeparator() was introducted in Java 7

Author: kris-sigur

src/test/java/org/archive/net/PublicSuffixesTest.java

@@ -36,7 +36,7 @@
  */
 public class PublicSuffixesTest extends TestCase {
     // test of low level implementation
-    private final String NL = System.lineSeparator();
+    private final String NL = System.getProperty("line.separator");
 
     public void testCompare() {
         Node n = new Node("hoge");