Buildbot proposal: combine portwatcher and portbuilder

[Mojca Miklavec]

Dear Ryan,

Please take a look at the discussion summary we just had at the meeting:

https://trac.macports.org/wiki/Meetings/MacPortsMeeting2018/BuildbotRestructuring

Regarding emails: we figured out that it makes no sense to make our
design decisions based on how annoying it would be to write emails. It
will probably be easier to write a separate set of scripts to send
individual emails separately.

Regarding the width of the waterfall: buildbot one solves that, the
waterfall is much leaner there :)

I have another request: could you please package buildbot 1.1 in a
Portfile? Ideally those who have buildbot installed now should get the
port replaced_by buildbot-0.8 and those who install it from scratch
should get buildbot version 1.0, but I'm not sure if MacPorts
currently support such a migration scheme. It would make more sense to
have buildbot 1.1 named "buildbot" and the old one named
"buildbot-0.8" though. Perhaps the new one should be called buildbot-1
after all, at least for a while, I don't know.

Mojca