clonebundle: support bundle2 exchange.readbundle() can return 2 different types. We weren't handling the bundle2 case. Handle it. At some point we'll likely want a generic API for applying a bundle from a file handle. For now, create another one-off until we figure out what the unified bundle API should look like (addressing this is a can of worms I don't want to open right now).

update: also use 'destupdate' for pull and unbundle Update can also be performed by 'hg pull --update' and 'hg unbundle'. We use the destupdate function in these case too.

destupdate: also include bookmark related logic For the same reason, we move the bookmark related update logic into the 'destupdate' function. This requires to extend the returns of the function to include the bookmark that needs to move (more or less) and the bookmark to activate at the end of the function. See function documentation for details on this returns.