Add a tool 'git-resurrect.sh <branch>' that tries to find traces of
the <branch> in the HEAD reflog and, optionally, all merge commits in
the repository. It can then resurrect the branch, pointing it at the
most recent of all candidate commits found.
Signed-off-by: Thomas Rast <trast@student.ethz.ch>
Signed-off-by: Junio C Hamano <gitster@pobox.com>