Bug 120544 [build path] Editing external source folder does not persist
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/wizards/buildpaths/BuildPathsBlock.java
item.setData(fLibrariesPage);
		item.setControl(fLibrariesPage.getControl(folder));
		
		
		Image cpoImage= JavaPluginImages.DESC_TOOL_CLASSPATH_ORDER.createImage();
		composite.addDisposeListener(new ImageDisposer(cpoImage));	
		
		ClasspathOrderingWorkbookPage ordpage= new ClasspathOrderingWorkbookPage(fClassPathList);		
		item= new TabItem(folder, SWT.NONE);
		item.setText(NewWizardMessages.BuildPathsBlock_tab_order); 
		item.setImage(cpoImage);
		item.setData(ordpage);
		item.setControl(ordpage.getControl(folder));
				
		if (fCurrJProject != null) {
			fSourceContainerPage.init(fCurrJProject);
			fLibrariesPage.init(fCurrJProject);
			fProjectsPage.init(fCurrJProject);
		}		
						
		Composite editorcomp= new Composite(composite, SWT.NONE);	
	
		DialogField[] editors= new DialogField[] { fBuildPathDialogField };
		LayoutUtil.doDefaultLayout(editorcomp, editors, true, 0, 0);
		
		int maxFieldWidth= converter.convertWidthInCharsToPixels(40);
		LayoutUtil.setWidthHint(fBuildPathDialogField.getTextControl(null), maxFieldWidth);
		LayoutUtil.setHorizontalGrabbing(fBuildPathDialogField.getTextControl(null));
	
		editorcomp.setLayoutData(new GridData(GridData.FILL_HORIZONTAL));