jenkins: Add scripts to make a release cut

This creates a new release publish by using the latest unstable
snapshots and merging those snapshots into a new pair of release
snapshots. In short, we do this:

  [mirror] debian -s\
                     > core-full-$stamp
  [repo]   core   -s/        \-s> $release-full-$stamp
                                       \-p> $release

  [repo]   $board-bsp
                \-s> unstable-bsp-$board-$stamp
                             \-s> $release-bsp-$board-$stamp
                                       \-p> $release-bsp-$board

Arrows with "s" in the middle are snapshot merges. A snapshot is created
from snapshots from the parent repo, mirror, or snapshot.

Arrows with "p" in the middle are publishes -- the final export to the
publicly viewable filesystem.

With this design, each release is freed from the upstream unstable churn
by one level of snapshots, which allows us to filter or merge in
packages from other snapshots, if necessary.

Change-Id: I4a2f6b0e4bbf8d8e8dd9b5eb575a524134bf912d
2 files changed