Install Tor Browser 5.0

Originally created by @intrigeri on #8548 (Redmine)

Of particular interest to us is that Tor Browser 5.0 will be based on Firefox esr38. The Tor Browser team is tracking this on:

Feature Branch: feature/8548-tor-browser-5.0

To upload designs, you'll need to enable LFS and have an admin enable hashed storage. More information