addrevision: use general delta when the incoming base delta is bad We unify the delta selection process to be a simple three options process: - try to use the incoming delta (if lazydeltabase is on) - try to find a suitable parents to delta against (if gd is on) - try to delta against the tipmost revision The first of this option that yield a valid delta will be used. The test change in 'test-generaldelta.t' show this behavior as we use a delta against the parent instead of a full delta when the incoming delta is not suitable. This as some impact on 'test-bundle.t' because a delta somewhere changes. It does not seems to change the test semantic and have been ignored.