Fixed issue with tooltip text not being escaped when no title is given

http://joomlacode.org/gf/project/joomla/tracker/?action=TrackerItemEdit&tracker_item_id=31321

This should solve the issues seen with the associations (see image).
![tooltips](https://f.cloud.github.com/assets/744259/742614/39a34298-e3d0-11e2-968e-993069c7adfa.png)

#### Testing Instructions
Check the associations column in the list views of - for example - the category manager.
Note: You'll need to have association languages setup up.