largefiles: respect the rev when reading standins in copytostore() (issue3630) When the rev isn't specified, the standin for the working copy gets read. But convert doesn't update the working copy for each cset it processes, so there is no standin and the 'hg convert' would abort complaining about the standin being missing. Note that if the largefile is not in the user cache, 'hg convert' complains about the largefile itself missing from the destination repo.

subrepo: subrepo isolation, pass baseui when cloning a new subrepo (issue2904) Create the repo with baseui because it should only get the global configuration. After this patch issue2904 is finally fixed.