Private Game Notification and enable enable share buttons for private projects

Logging this on behalf of Keith. 

"I’m raising this as a usability issue, as it can be confusing for the player. When going to a private project teaser, this shows up. In my opinion, there is no need to obfuscate any private projects at the expense of confusing the player. This screen should instead prompt a log-in screen, and following which, it can then display this screen."

"please enable share buttons for private projects too".