In this change, you will be able to encrypt your site with SSL
(http://your-site >>> https://your-site).
This change will help when you create a private site.
Default value of "Admin" > "General" > "Preferred site URL" has been changed.
Before: "http://" + your site (Protocol absolute URL)
After: "//" + your site (Protocol relative URL)
[2016/04/01] These changes seem to affect processing of Q2A. So, these changes has been rollbacked.