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
private RefreshAction fRefreshAction;
 	private BackAction fBackAction;
	private ForwardAction fForwardAction;
	private GoIntoAction fZoomInAction;
	private UpAction fUpAction;
	private GotoTypeAction fGotoTypeAction;
	private GotoPackageAction fGotoPackageAction;
	private AddBookmarkAction fAddBookmarkAction;
	
 	private FilterSelectionAction fFilterAction;
 	private ShowLibrariesAction fShowLibrariesAction;
	private ShowBinariesAction fShowBinariesAction;
	private FilterWorkingSetAction fFilterWorkingSetAction;
	private RemoveWorkingSetFilterAction fRemoveWorkingSetAction;
	private IMemento fMemento;
	
	private ISelectionChangedListener fSelectionListener;
	
	private IPartListener fPartListener= new IPartListener() {
		public void partActivated(IWorkbenchPart part) {
			if (part instanceof IEditorPart)
				editorActivated((IEditorPart) part);
		}
		public void partBroughtToTop(IWorkbenchPart part) {
		}
		public void partClosed(IWorkbenchPart part) {
		}
		public void partDeactivated(IWorkbenchPart part) {
		}
		public void partOpened(IWorkbenchPart part) {