Issue 719 Fix

[Issue Link](https://github.com/bountysource/frontend/issues/719)

I added a name attribute to each of the profile photo radio buttons so they would be treated as a group. I also updated the value attributes of these photos to utilize ng-value. I set the current photo's value to "" so there would not be two radio buttons with the same value.

The radio button currently selected is the last instance of the current profile photo. i.e if you are using the twitter profile photo, the twitter profile radio button will be selected rather than the current radio button.