Ports for buildbot 3

[Mojca Miklavec]

Hi,

Buildbot 3 (that is slightly incompatible with buildbot 2) has
recently been released.

We currently ship:
- buildbot-0.8, buildbot-slave-0.8
- buildbot, buildbot-worker (+ dependencies) that provide version 2

So we are basically lacking buildbot 1.x and the new 3.x.

I don't see any need to ship version 1.x which is very similar to 2.x,
but version 3.x removed a lot of deprecated APIs (from what I
understand a well-written configuration should still work on 3.x, so
it's not as bad as the migration from 0.8 to 1.x).

I would like to update to version 3.x, but I would be grateful for
agreement about what ports we want to end up with before doing any
changes to the ports.

(I'm still trying to figure out whether buildbot-worker 3.x is
incompatible with buildbot master 1.x or 2.x. If it's compatible, we
don't need to provide version 2 of the worker.)

Thank you,
    Mojca