Merge branch 'rs/branch-del-symref'

A symbolic ref refs/heads/SYM was not correctly removed with "git branch -d SYM"; the command removed the ref pointed by SYM instead. * rs/branch-del-symref: branch: show targets of deleted symrefs, not sha1s branch: skip commit checks when deleting symref branches branch: delete symref branch, not its target branch: factor out delete_branch_config() branch: factor out check_branch_commit()