Give users a way to ask for opinions

Fixes #361. This gives the user a button below all the nitpicks on the submission screen if there is a nitpick AND the user commented on it. After it's clicked, it changes to a 'turn this off' type of button. 

When submissions have this flag set to true, they show up a bit differently in the dashboard. The middle circle (responses) turns from blue to yellow-ish, and the number turns into a bullhorn icon. This color and icon are easy to change if there are other ideas about how that should look. 

I think that's about it. Let me know if there's anything that needs tweaked. Cheers!