Providing Nested Check Buttons to give a user more backup options for a single application.

Nested check buttons, like the way Eclipse does(http://i27.tinypic.com/16kxtts.jpg), will make sure that we can provide the user with multiple backup options for a single application. This issue came up while providing the user with 2 separate buttons for backing up either account info or the logs in empathy(https://code.launchpad.net/~stipple-devs/stipple/stipple-empathy/+merge/30775). So, for complex applications where a user might consider multiple backup options(logs, settings etc.), such buttons will make the task easier. As of now, I am not sure if its possible in PyGTK but we can probably do something similar or better using it later.