Removal of 2.6.39-bpo

[Ram Natarajan <ram@cradle.com>]

Hi Folks,
It would be good if there is a clear warning message that backport archives can
suddenly disappear from the repository without warning. This is to ensure that
people do not use the backport archives like the stable ones assuming that it
will be available in the future.
Here is what happened - I had installed 2.6.39 backport kernel on my machine. A
few months later, I wanted to build a kernel module and found that
linux-headers-2.6.39-bpo.2-686-pae has disappeared from the repository. Yes - I
do know that the latest bpo kernel is 3.2, but it would have been good to warn
me. I would have, at the least, made a local copy of all the necessary archive
files.
-Ram