Debug tables wraps content [SKIP CI]

This small change is to avoid table content overflow when the text hasn't spaces to break words.
For example, this: 

![yii debugger 2013-12-18 23-09-58](https://f.cloud.github.com/assets/374554/1779931/fe6697d2-685b-11e3-950b-ac4804dc6864.png)

becomes:

![yii debugger 2013-12-18 23-12-38](https://f.cloud.github.com/assets/374554/1779932/0868c156-685c-11e3-88a7-dfa7d5a15112.png)