Rewrite the event comment email.

Rather than a list of key/value pairs, create an email with a useful
subject line and body copy that looks good. Also provide a link to
the comments section of the event.

Example subject line:
Joind.in event feedback for Web day

Example body:
A new comment has been added to the Ruby day event by estephens on 5th Jan 2013 at 12:37:

My best camp so far, i liked Ryan's talk and Lukes the most

also IRC was amazing

I think it is nice to have more time for questions
and even a session that is more hands on

View on website: http://joindin.localhost/event/view/212#comments
Codesniff cleanup
Merge branch 'better-event-feedback-email'