Merge branch 'sg/complete-refs'

* sg/complete-refs: completion: remove broken dead code from __git_heads() and __git_tags() completion: fast initial completion for config 'remote.*.fetch' value completion: improve ls-remote output filtering in __git_refs_remotes() completion: query only refs/heads/ in __git_refs_remotes() completion: support full refs from remote repositories completion: improve ls-remote output filtering in __git_refs() completion: make refs completion consistent for local and remote repos completion: optimize refs completion completion: document __gitcomp() Conflicts: contrib/completion/git-completion.bash