[tz] 2016b is on GitHub

Given the urgency of the Haiti rule change in a few hours, I've prepared a new tz version 2016b. It is available at <https://github.com/eggert/tz> as commit 70161f48bc212678c58490f7faabc286c90b2a05. Although this is intended to be the next release, published as usual, it can take a bit of time to turn the crank so I thought I'd give the mailing list a heads-up. 2016b does not incorporate all changes recently circulated. Notably it's missing historical changes for Russia contributed by Stepan Golosunov, which I haven't had time to proofread carefully. I'd like to get all this stuff fixed soon, although we may have to wait until the spring silly season is over.