Update on 3.0, 3.1, and 3.2.

[Alan DeKok]

  We plan on releasing 3.0.12 on Monday.  it's stable, and there no new issues being reported for it.

  This will ideally be the last release of the 3.0 series.  Version 3.0 was released almost three years ago, and it's time for a new major version of the server.  3.1 supports a "map" keyword, redis cluster, and many other useful features.

  Many people have been using the 3.1 branch in production, so we're confident that it is stable and functional.  To keep things simple, we don't release an official 3.1 version.  Instead, we will call 3.1 a "development / experimental" branch.

  Once we're ready (later this summer), we'll release an official 3.2 release.  The v3.1.x branch will then be frozen, and no further development will occur on it.

  All new development will then start with a 3.3 branch, which will likely turn into version 4.0.  There are enough architecture changes needed that it warrants a 4.0.

  In summary:

2.1 and earlier: dead.  Don't use them.

2.2: Only critical security fixes.  We expect this won't happen.

3.0: stable.  New installations can use 3.0.

3.1: development.  Use it only if you know what you're doing.

3.2: (future stable).  Mid 2016 on, new installations should use this.

3.3. (future development), more changes, with a goal of increasing performance substantially.