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
Consistency
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(It's been replaced by ```batch_subscription_notification```.)
Merge pull request #1195 from CristinaRO/issue-3274-recipient-notification

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