Merge branch 'maint-1.6.1' into maint-1.6.2

* maint-1.6.1:
  Documentation: git-archive: mark --format as optional in summary

Author: gitster

Documentation/git-archive.txt

@@ -9,7 +9,7 @@ git-archive - Create an archive of files from a named tree
 SYNOPSIS
 --------
 [verse]
-'git archive' --format=<fmt> [--list] [--prefix=<prefix>/] [<extra>]
+'git archive' [--format=<fmt>] [--list] [--prefix=<prefix>/] [<extra>]
 	      [--remote=<repo> [--exec=<git-upload-archive>]] <tree-ish>
 	      [path...]