Merge branch 'jc/name-branch'

* jc/name-branch: Don't permit ref/branch names to end with ".lock" check_ref_format(): tighten refname rules strbuf_check_branch_ref(): a helper to check a refname for a branch Fix branch -m @{-1} newname check-ref-format --branch: give Porcelain a way to grok branch shorthand strbuf_branchname(): a wrapper for branch name shorthands Rename interpret/substitute nth_last_branch functions Conflicts: Documentation/git-check-ref-format.txt