Now sending email on getting a review:

whenever someone reviews a solution, solution's author might get a review
(depending on a setting).
Tweaked notification email body.
Reacting to code review (#273).
Merge remote-tracking branch 'upstream/master' into 92_email_notifications
Merge remote-tracking branch 'upstream/master' into 92_email_notifications
Merge pull request #273 from egor83/92_email_notifications

Sending email on getting a review (fixes #92)