Bug 73984 Editing user library jar path after path change does not work [build path]
1) Create a directory containing jar file 2) Add this jar file to a new user library 3) Rename directory from 1) 4) Update the path to jar file in user libraries (select old jar reference, select new location in browser, open -> path is not updated, but old path is still used
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/UserLibraryPreferencePage.java
elements.add(new CPUserLibraryElement(names[i], container));
			} catch (JavaModelException e) {
				JavaPlugin.log(e);
				
			}
		}
		fLibraryList.setElements(elements);
		fLibraryList.setViewerSorter(new CPListElementSorter());
		
		doSelectionChanged(fLibraryList);  
	}
	
	public static IJavaProject getPlaceholderProject() {
		String name= "####internal"; 
		IWorkspaceRoot root= ResourcesPlugin.getWorkspace().getRoot();
		while (true) {
			IProject project= root.getProject(name);
			if (!project.exists()) {
				return JavaCore.create(project);
			}
			name += '1';
		}		
	}
	
	
	/**
	 * Constructor to be used when programatically showing the page
	 * @param selectedLibrary The entry to be selected by default. 
	 * @param createIfNotFound Create the library if not found
	 */