* builds the UI
*/
protected final void build() {
tabbedPane = new JTabbedPane();
propertiesMerger = new PropertiesMerger();
propertiesMerger.setName("panel.propertiesmerger");
propertiesMerger.getModel().addPropertyChangeListener(this);
tabbedPane.add(tr("Properties"), propertiesMerger);
tagMerger = new TagMerger();