blackberry/bbUI.js — pull request #668 by kquinsland (2013-02-08 01:59:21+00:00)
Title: added popToScreenNumber(screenNumber)

added popToScreenNumber(sn).

Usage:

```javascript

// removes all screens on stack added after 3
// goes back to the 3rd screen pushed onto screen stack
bb.popToScreenNumber(3);

```