Displaying Enrollment Mode on Enrollment Activity Page

![screen shot 2014-10-24 at 3 57 08 pm](https://cloud.githubusercontent.com/assets/910510/4775506/9e6ec7ea-5bb8-11e4-8ac1-9d6ed311a8a8.png)

@rocha @dsjen @marcotuts @shnayder @lamagnifica 
`display_verified_enrollment` seems to imply that verified enrollments will be displayed.  Perhaps something like `is_verified_enrollment_displayed` would be more accurate.