Bug 174272 FileStoreEditorInput needs to be restorable
3.3 M5 The FileStoreEditorInput needs to restorable on startup. Therefore it needs to return an IPersistableElement and there needs to be an element factory.
bundles/org.eclipse.ui.ide/src/org/eclipse/ui/ide/IDE.java
private static IEditorDescriptor getEditorDescriptor(String name,
			IEditorRegistry editorReg, IEditorDescriptor defaultDescriptor)
			throws PartInitException {
		if (defaultDescriptor != null) {
			return defaultDescriptor;
		}
		IEditorDescriptor editorDesc = defaultDescriptor;
		
		if (editorReg.isSystemInPlaceEditorAvailable(name)) {
			editorDesc = editorReg
					.findEditor(IEditorRegistry.SYSTEM_INPLACE_EDITOR_ID);
		}
		
		if (editorDesc == null
				&& editorReg.isSystemExternalEditorAvailable(name)) {
			editorDesc = editorReg
					.findEditor(IEditorRegistry.SYSTEM_EXTERNAL_EDITOR_ID);
		}
		
		if (editorDesc == null) {
			editorDesc = editorReg
					.findEditor(IDEWorkbenchPlugin.DEFAULT_TEXT_EDITOR_ID);
		}
		
		if (editorDesc == null) {
			throw new PartInitException(
					IDEWorkbenchMessages.IDE_noFileEditorFound);
		}
		return editorDesc;
	}