Added missing IDs in xml files

src/uk/co/majenko/audiobookrecorder/AudiobookRecorder.java

@@ -1020,7 +1020,6 @@ public class AudiobookRecorder extends JFrame {
 
     @SuppressWarnings("unchecked")
     void treePopup(MouseEvent e) {
-
         int selRow = bookTree.getRowForLocation(e.getX(), e.getY());
         TreePath selPath = bookTree.getPathForLocation(e.getX(), e.getY());
         if (selRow != -1) {

src/uk/co/majenko/audiobookrecorder/Chapter.java

@@ -46,6 +46,7 @@ public class Chapter extends DefaultMutableTreeNode {
     public Chapter(Element root, DefaultTreeModel model) {
 
         name = Book.getTextNode(root, "name");
+        id = root.getAttribute("id");
         preGap = Utils.s2i(Book.getTextNode(root, "pre-gap"));
         postGap = Utils.s2i(Book.getTextNode(root, "post-gap"));