Migrate to Firefox 31 ESR

Resources:

• Support building TBBs based on Fx31 from Gitian

Feature Branch: feature/tor-browser-bundle

Subtasks

• #7236 (closed)
• #7542 (closed)
• #7964 (closed)
• #7972 (closed)
• #7985 (closed)
• #8026 (closed)

Related issues

• Related to #7953 (closed)

Original created by @intrigeri on 7238 (Redmine)