Create setParameter to control creation of rollback data files

During rollback, replication writes out data files that contain documents that will be deleted after rollback completes. This means that the time it takes to execute a rollback scales linearly with the amount of data that has been inserted after the common point.

There may be cases when a user might not care about these deleted documents and simply want rollback to execute as fast as possible. We can add a startup-only setParameter that controls whether or not these rollback data files will be created or not; the default behavior will be to always write out data files.