Fixes the recipient notification email (HTML); adds recipient notification email text
Fixes to various emails

Abuse report text version had an extra ')'.
Co-author notification text version had an extra '='.
Prompter notification text version had too many newlines.
Recipient notification text version was missing, and then had html tags and extra newlines.
Subscription notification didn't have a text version.
Begone, stray double quote!
Compact, compress, con...text?

More whitespace chasing.

Missing @ in the prompter notification emails.

Unless encompasses all of the Fandom line now.
Gnrgh
2933ish further tweaks to the error page which was getting styling from the error flash messages that led to ugliness
Add dropdown jquery and improve formatting of static error page files
Rearrange footer development links
3293 footer escaping outer wrapper
That only worked because caching
Consistency
Merge pull request #1196 from sarken/issue_3293

3293 footer escaping outer wrapper
Merge pull request #1186 from sarken/issue_2933_error_page_tweaks

Issue 2933 static error/placeholder page tweaks
Removing traces of Airbrake (which may be causing errors)
Turns out we're not even using subscription_notification any longer

Removing deprecated ```subscription_notification``` user_mailer method, and its corresponding views.

(It's been replaced by ```batch_subscription_notification```.)
Removing Airbrake gem
Merge pull request #1197 from elzj/airbrake_removal

Removing Airbrake
Merge pull request #1195 from CristinaRO/issue-3274-recipient-notification

Fixes the recipient notification email (HTML); adds recipient notification email text