Cleanup IDE quit()

There were two different routines andling more or less the same operations.
Let the IDE call "real" quit when the last Editor windows is being closed.

app/src/processing/app/Base.java

@@ -925,45 +925,20 @@ public class Base {
    */
   public boolean handleClose(Editor editor) {
     // Check if modified
-//    boolean immediate = editors.size() == 1;
     if (!editor.checkModified()) {
       return false;
     }
 
     if (editors.size() == 1) {
-      storeScreenDimensions();
-      storeSketches();
 
-      // This will store the sketch count as zero
-      editors.remove(editor);
-      try {
-        Editor.serialMonitor.close();
-      } catch (Exception e) {
-        //ignore
-      }
-      rebuildRecentSketchesMenuItems();
-
-      // Save out the current prefs state
-      PreferencesData.save();
-
-      // Since this wasn't an actual Quit event, call System.exit()
-      System.exit(0);
+      handleQuit();
 
     } else {
       // More than one editor window open,
       // proceed with closing the current window.
       editor.setVisible(false);
       editor.dispose();
-//      for (int i = 0; i < editorCount; i++) {
-//        if (editor == editors[i]) {
-//          for (int j = i; j < editorCount-1; j++) {
-//            editors[j] = editors[j+1];
-//          }
-//          editorCount--;
-//          // Set to null so that garbage collection occurs
-//          editors[editorCount] = null;
-//        }
-//      }
+
       editors.remove(editor);
     }
     return true;