Bug 11748 switch to new DecoratorManager API
From the workbench change notes: API changes IWorkbenchPartSite.getDecoratorManager() - As the DecoratorManager has proven to be required for more than just IWorkbenchPartSites we have moved getDecoratorManager() to IWorkbench and deprecated the getDecoratorManager() in IWorkbenchPartSite. The one in IWorkbenchPartSite will be removed after the other Eclipse components have had a chance to switch to the new API.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/packageview/PackageExplorerPart.java
menu.add(new Separator());
		if (fPropertyDialogAction.isApplicableForSelection())
			menu.appendToGroup(IContextMenuConstants.GROUP_PROPERTIES, fPropertyDialogAction);	
	}
	 void addGotoMenu(IMenuManager menu) {
		MenuManager gotoMenu= new MenuManager(PackagesMessages.getString("PackageExplorer.gotoTitle")); 
		menu.appendToGroup(IContextMenuConstants.GROUP_GOTO, gotoMenu);
		gotoMenu.add(fBackAction);
		gotoMenu.add(fForwardAction);
		gotoMenu.add(fUpAction);
		gotoMenu.add(fGotoTypeAction);
		gotoMenu.add(fGotoPackageAction);
	}
	private boolean onlyFilesSelected(IStructuredSelection selection) {
		if (selection.isEmpty())
			return false;
		for (Iterator enum= selection.iterator(); enum.hasNext();) {
			Object o= enum.next();
			if (o instanceof IFile)
				continue;
			if (o instanceof IAdaptable) {
				Object resource= ((IAdaptable)o).getAdapter(IResource.class);
				if (!(resource instanceof IFile))
					return false;
			} else {
				return false;
			}
		}
		return true;
	}