Bug 120544 [build path] Editing external source folder does not persist
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/SourceContainerWorkbookPage.java
buttonLabels= new String[] { 
			NewWizardMessages.SourceContainerWorkbookPage_folders_add_button, 
			NewWizardMessages.SourceContainerWorkbookPage_folders_link_source_button,
			 null,
			NewWizardMessages.SourceContainerWorkbookPage_folders_edit_button, 
			NewWizardMessages.SourceContainerWorkbookPage_folders_remove_button
		};
		
		fFoldersList= new TreeListDialogField(adapter, buttonLabels, new CPListLabelProvider());
		fFoldersList.setDialogFieldListener(adapter);
		fFoldersList.setLabelText(NewWizardMessages.SourceContainerWorkbookPage_folders_label); 
		
		fFoldersList.setViewerSorter(new CPListElementSorter());
		fFoldersList.enableButton(IDX_EDIT, false);
		
		fUseFolderOutputs= new SelectionButtonDialogField(SWT.CHECK);
		fUseFolderOutputs.setSelection(false);
		fUseFolderOutputs.setLabelText(NewWizardMessages.SourceContainerWorkbookPage_folders_check); 
		fUseFolderOutputs.setDialogFieldListener(adapter);
	}
	
	public void init(IJavaProject jproject) {
		fCurrJProject= jproject;	
		updateFoldersList();
	}
	
	private void updateFoldersList() {	
		ArrayList folders= new ArrayList();
	
		boolean useFolderOutputs= false;