MB-9307: Don't include new partitions due to rollback

When a rollback is performed, the new header might contain
partitions that are not part of the current index. Mark those
for cleanup and update the header accordingly.

Change-Id: If5ddc95a1ef8866418d0bffcc4eff4773ac227b0
Reviewed-on: http://review.couchbase.org/30023
Reviewed-by: Volker Mische <volker.mische@gmail.com>
Tested-by: Volker Mische <volker.mische@gmail.com>