[tz] A rollup tz release would be helpful

There have been a pretty substantial number of refactoring and cleanup changes to the experimental tz repository over the last month, and things now seem to be settling down. Speaking as the person who does a fair amount of the integration of tz releases into Google, I would definitely find it helpful to have an official release that includes these changes happen sooner rather than later. Past experience suggests that there may be a few internal glitches to be sorted through, and I would far prefer to handle them now, while not under pressure to get some low-lead-time rule change deployed in a hurry. We only deploy official tz releases, not informal repository snapshots. Thanks, -- Andy