Merge branch 'status-no-lock-index'

This branch allows third-party tools to call `git status
--no-lock-index` to avoid lock contention with the interactive Git usage
of the actual human user.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

Documentation/git-status.txt

@@ -115,7 +115,6 @@ configuration variable documented in linkgit:git-config[1].
 	without options are equivalent to 'always' and 'never'
 	respectively.
 
-<pathspec>...::
 	See the 'pathspec' entry in linkgit:gitglossary[7].
 
 OUTPUT

builtin/commit.c

@@ -1350,6 +1350,7 @@ static int git_status_config(const char *k, const char *v, void *cb)
 
 int cmd_status(int argc, const char **argv, const char *prefix)
 {
+	static int no_lock_index = 0;
 	static struct wt_status s;
 	int fd;
 	struct object_id oid;
@@ -1381,6 +1382,8 @@ int cmd_status(int argc, const char **argv, const char *prefix)
 		  N_("ignore changes to submodules, optional when: all, dirty, untracked. (Default: all)"),
 		  PARSE_OPT_OPTARG, NULL, (intptr_t)"all" },
 		OPT_COLUMN(0, "column", &s.colopts, N_("list untracked files in columns")),
+		OPT_BOOL(0, "no-lock-index", &no_lock_index,
+			 N_("do not lock the index")),
 		OPT_END(),
 	};