bundle: include required phases when saving a bundle (issue6794) We now properly computes and includes phases above secret in bundle, previously, they would be skipped, and then the code computing them would crash. Note that from this changeset, we also include the heads associated with the changegroup's "target" phase. This turned out to be necessary to ensure the movement of changeset included in the bundle, but already known locally. This explain why lines for "secret" heads appears in multiple tests.