Merge pull request #2533 from awesomerobot/master

fixing onebox image width bug
further improvements to Admin Quick Start Guide
Revert "FEATURE: reject accounts created with an email address similar to a known spammer email"

This reverts commit 39be48a441cda05e7efafefcd919326731778625.

Conflicts:
	spec/models/screened_email_spec.rb
SECURITY: Don't allow badges on read restricted categories
FEATURE: reject accounts created with an email address similar to a known spammer email
add safety for max levenshtein spammer distance
FIX: appears broken in multisite
Merge branch 'master' of github.com:discourse/discourse
fixing appearance of horizontal scrollbar on topic list at about 996px wide