6.4.1 update

[Simon Marlow]

Hi Folks,

I'm back, and it's high time we released 6.4.1.  The bug reports keep on
rolling in, but I think there are only a few blockers and the rest can
be pushed back to 6.4.2 (long gone are the days when we used to be able
to claim that all outstanding bugs have been fixed!).

I'll set a tentative release date for next Monday (19 Sept).  If there's
anything still broken in the release candidate that is really holding
you up, please let us know (unless I've already sent an email about it
in the last couple of days in which case it'll be paged in).  Things I
hope to look into before the release:

  - building GHC with an upgraded Cabal (Duncan Coutts)
  - crashes when compiling Pugs (Gaal Yahas)
  - scavenge_stack crash (Jason Dagit)

Cheers,
	Simon