context: explicitly return a tuple In the refactoring of removing localrepo.status, 2edb8648c500, we accidentally changed the return type from a tuple to a list. Philosophically, this is incorrect so we explicitly return a tuple again.

wireproto: expose the list of getbundle arguments to extensions For now, getbundle accepts a fixed number of arguments: ``heads``, ``common`` and ``bundlecaps``. We make this list exposed at the module level to let extensions add content there. This is important for extensions that wish to use bundle2 for other contents than changegroup.