Minor tweaks to the listing of frames.

Hi, 

I've made two small adjustments to how the frames are listed on the left-hand side:

 - The 'common part' of paths is omitted for brevity
 - I've added 'soft hyphens', so the lines can wrap more naturally. 

Screenshot before:

![Screen Shot 2013-04-06 at 3 39 20 PM](https://f.cloud.github.com/assets/1833361/347320/8563643c-9ec1-11e2-8db7-4248c63d887b.png)

Screenshot after: 

![Screen Shot 2013-04-06 at 3 38 14 PM](https://f.cloud.github.com/assets/1833361/347322/8c195750-9ec1-11e2-9459-e1b24109dcb1.png)