Merge branch 'maint'

* maint:
  complete: zsh: use zsh completion for the main cmd
  complete: zsh: trivial simplification
  git-completion.bash: complete branch.*.rebase as boolean
  git-completion.bash: add diff.submodule to config list
  git-completion.bash: lexical sorting for diff.statGraphWidth

contrib/completion/git-completion.bash

@@ -1819,6 +1819,10 @@ _git_config ()
 		__gitcomp_nl "$(__git_refs)"
 		return
 		;;
+	branch.*.rebase)
+		__gitcomp "false true"
+		return
+		;;
 	remote.*.fetch)
 		local remote="${prev#remote.}"
 		remote="${remote%.fetch}"
@@ -1858,6 +1862,10 @@ _git_config ()
 			"
 		return
 		;;
+	diff.submodule)
+		__gitcomp "log short"
+		return
+		;;
 	help.format)
 		__gitcomp "man info web html"
 		return
@@ -2052,13 +2060,14 @@ _git_config ()
 		core.whitespace
 		core.worktree
 		diff.autorefreshindex
-		diff.statGraphWidth
 		diff.external
 		diff.ignoreSubmodules
 		diff.mnemonicprefix
 		diff.noprefix
 		diff.renameLimit
 		diff.renames
+		diff.statGraphWidth
+		diff.submodule
 		diff.suppressBlankEmpty
 		diff.tool
 		diff.wordRegex