Also adds test case for providing an invalid 2FA code and then a valid
one without re-entering username and password.

"Two-factor" vs. "2-Factor"

Turn 2-factor authentication into 2 steps process. Disabled 2fa UI for ldap users since it is not supported

Remove class and id attributes from SanitizationFilter whitelist

Closes internal https://dev.gitlab.org/gitlab/gitlabhq/issues/2302

See merge request !631

Fix Firefox problems when it wants to render issuable component

Move project visibility from clone bar to repository details block for non empty project.

See merge request !1818

How to reset your root password

Added link and file correctly on Security doc.

Please review to make sure it's correct.

See merge request !1811

Added X-GitLab-Event header for web hooks

Adding quote_string to migration

See merge request !630

Fix link to the CI documentation

See merge request !627

Improved the backup documentation

See merge request !621