Improved Referer Handling
The Torbutton master branch has some code for improving referer handling, courtesy of Kory Kirk. However, a potentially better strategy for only proving referer headers to page elements has been implemented by JonDos: http://www.jondos.org/en/node/1754.
It's possible that FactorBee also provides something like this, but it is too hard to communicate and interact with its author. The preferred reference implementation should be the JonDos version.
JonDos also claims to have improved certificate store protections in that release that are worth investigating.