Bug 63267 [RCP] tab style for M9
the tab style in the IDE in M9 should use the curved style
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/internal/ide/IDEWorkbenchAdvisor.java
newlyAddedFeatures = new TreeSet(currentFeatures);
		newlyAddedFeatures.removeAll(previousFeatures);
		
	}
	/*
	 * Open a welcome editor for the given input
	 */
	private void openWelcomeEditor(IWorkbenchWindow window, WelcomeEditorInput input, String perspectiveId) {
		if (getWorkbenchConfigurer().getWorkbench().getWorkbenchWindowCount() == 0) {
			
			
			return;
		}
	
		IWorkbenchWindow win = window;
		if (perspectiveId != null) {
			try {
				win = getWorkbenchConfigurer().getWorkbench().openWorkbenchWindow(perspectiveId, getDefaultPageInput());
				if (win == null) {
					win = window;
				}
			} catch (WorkbenchException e) {
				IDEWorkbenchPlugin.log("Error opening window with welcome perspective.", e.getStatus()); 
				return;
			}
		}
	
		if (win == null) {
			win = getWorkbenchConfigurer().getWorkbench().getWorkbenchWindows()[0];