Write a pluggable transport deployment roadmap

This ticket is about coming up with a plan for making pluggable transports work in practice, including how to solve the packaging and updating problems. The output document will describe ways for rolling out new protocols in the future, even though the initial deployment will only contain obfs2 as transport. The document will also cover how BridgeDB will give out transport information to bridge users. Basically, the document will describe what users will have to do to use pluggable transports: download a special bundle, learn bridges that support one or more pluggable transports, put the Bridge lines into the torrc or Vidalia, done. The document will also describe how Tor uses UPnP to set up port forwarding to the bridge proxy.

This ticket is part of the March 31, 2012 milestone for sponsor G.