Linux 3.15 .. and continuation of merge window

So I ended up doing an rc8 because I was a bit worried about some
last-minute dcache fixes, but it turns out that nobody seemed to even
notice those. We did have other issues during the week, though, so it
was just as well. The futex fixes and cleanups may stand out, but as
usual there's various other random fixes since rc8 in there too:
mainly drivers (drm, networking, sound, usb etc), networking,
scheduling and perf tooling.

But it's all been fairly small and quiet, which *may* of course be due
to the fact that last week was also the first week of the merge window
for 3.16. That might have distracted some developers. I'm not entirely
convinced I liked the overlap, but it seemed to work ok, and unless
people scream really loudly ("Please don't _ever_ do that again") and
give good reasons for doing so, I might end up doing that overlapping
merge window in the future too if it ends up helping out with some
particular timing issue.

That said, I also don't think it was such a wonderful experience that
I'd want to necessarily do the overlap every time, without a good
specific reason for doing so. It was kind of nice being productive
during the last week or rc (which is usually quite boring and dead),
but I think it might be a distraction when people should be worrying
about the stability of the rc.

Of course, maybe the overlap ends up meaning that we get less noise
during the last week of stabilization, and it actually helps. It could
go either way. I'd be interested to hear what people thought, although
I _suspect_ most people don't feel strongly either way.

Anyway, with 3.15 released, my "master" branch has already merged the
work in my "next" branch on my local machine, and I'll be
decommissioning the "next" branch once I push that all out. After
that, any future merge window work will happen on "master", and we'll
be back to the normal single-branch model for my tree.