add -b/--branch option to clone, bundle, incoming, outgoing, pull, push

subrepo: change default path in hgrc of subrepo after cloning Previous behavior was to put in the cloned subrepos the path found in the original main repo. However it isn't valid for relative path and it seems more logical to reference instead the subrepos working copy path of the original main repo.

streamclone: allow uncompressed clones by default