I think this is a good idea, but in the mean time, you can scroll through commit history looking for relevant comments or the date of that last known stable release, or click on "releases" on git hub, then click the hash stub of the appropriate release, copy the hash and just checkout that commit locally then checkout -b for your tinkering. Now that I look though, it seems there are no longer any releases or tags for anything prior to 2014-2-2 :/

I guess you probably already know all that. I had to checkout previous commits a few times in the last few weeks and didn't have too much trouble finding the appropriate versions, granted I probably pay too much attention to cbuchner's commits (I read the commit log more often than I do this thread)