* jc/clone:
git-clone: typofix.
clone: record the remote primary branch with remotes/$origin/HEAD
revamp git-clone (take #2).
revamp git-clone.
fetch,parse-remote,fmt-merge-msg: refs/remotes/* support
* jc/name:
sha1_name: make core.warnambiguousrefs the default.
sha1_name: warning ambiguous refs.
get_sha1_basic(): try refs/... and finally refs/remotes/$foo/HEAD
core.warnambiguousrefs: warns when "name" is used and both "name" branch and tag exists.