Display the item title instead of the item ID on the typeahead forms for widgets

Fixes #321 

![screen shot 2014-02-24 at 13 29 13](https://f.cloud.github.com/assets/111218/2251269/bf6909c4-9d9a-11e3-9686-93f8772ad196.png)
![screen shot 2014-02-24 at 13 29 06](https://f.cloud.github.com/assets/111218/2251270/bf7c55d8-9d9a-11e3-943f-816e8544db2f.png)