Allow more lines of text for titles of break slots

Allow up to 3 lines of text for titles of break slots since there is no detail view for them where users can see the full title.

Before:
![iosched_break_title_before__cropped](https://cloud.githubusercontent.com/assets/218061/4912216/34dc84bc-649a-11e4-86dc-f2596f6cf211.png)

After:
![iosched_break_title_after__cropped](https://cloud.githubusercontent.com/assets/218061/4912217/3a4438dc-649a-11e4-90c2-8625b13de3c5.png)