Add the ability to operate as an exit enclave exclusively

I would like to setup exit enclaves for all of the public facing services that I manage. However, I would like these exit enclaves to just be exit enclaves, and not be routing other tor traffic through them as an intermediary.

I want to contribute to the tor network by routing tor network traffic, providing a bridge and an exit node, but I prefer to separate these logically and topologically in our network and not bundle them together. This is especially true because I've got multiple services in the same rack that are all configured identically that I would like each to exit enclave for their services that they provide to the public, but not each individually be routing tor traffic as intermediaries.

I would like to route tor traffic for others, but on a different box (and on a different network in some cases), but not when I am exit enclaving.

[Automatically added by flyspray2trac: Operating System: All]