Reportback Flag form - front end

Heaven help me I wrote jQuery today. :christmas_tree: 

Refs #3564.

Adds form elements for the Flag reportback form, which are only displayed when "flagged" is checked.

Doesn't actually write any values yet, as the first priority is to get a prototype up for campaigns team to test.

![screen shot 2014-12-09 at 3 42 11 pm](https://cloud.githubusercontent.com/assets/1236811/5365443/faefa73a-7fb9-11e4-9dc6-819e6339b6d0.png)
It's pretty nasty code, since I'm using the `$form['rb_files']['#tree'] = TRUE;`, each id and name is uniqiue.  Here's what the markup looks like:
````
<input type="radio" id="edit-rb-files-1462-status-approved" name="rb_files[1462][status]" value="approved" class="form-radio">
````
![screen shot 2014-12-09 at 3 49 48 pm](https://cloud.githubusercontent.com/assets/1236811/5365557/2471db5e-7fbb-11e4-9c6f-41ae5070b2a7.png)