i18n: git-status "nothing to commit" messages

Gettextize the "nothing to commit" messages. Many tests explicitly
checked for this message. Change them to skip under
GETTEXT_POISON=YesPlease.

Signed-off-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7506-status-submodule.sh

@@ -20,12 +20,12 @@ test_expect_success 'setup' '
 	git commit -m "Add submodule sub"
 '
 
-test_expect_success 'status clean' '
+test_expect_success C_LOCALE_OUTPUT 'status clean' '
 	git status >output &&
 	grep "nothing to commit" output
 '
 
-test_expect_success 'commit --dry-run -a clean' '
+test_expect_success C_LOCALE_OUTPUT 'commit --dry-run -a clean' '
 	test_must_fail git commit --dry-run -a >output &&
 	grep "nothing to commit" output
 '
@@ -177,12 +177,12 @@ test_expect_success 'rm submodule contents' '
 	rm -rf sub/* sub/.git
 '
 
-test_expect_success 'status clean (empty submodule dir)' '
+test_expect_success C_LOCALE_OUTPUT 'status clean (empty submodule dir)' '
 	git status >output &&
 	grep "nothing to commit" output
 '
 
-test_expect_success 'status -a clean (empty submodule dir)' '
+test_expect_success C_LOCALE_OUTPUT 'status -a clean (empty submodule dir)' '
 	test_must_fail git commit --dry-run -a >output &&
 	grep "nothing to commit" output
 '

wt-status.c

@@ -763,14 +763,14 @@ void wt_status_print(struct wt_status *s)
 				advice_status_hints
 				? _(" (use \"git add\" to track)") : "");
 		else if (s->is_initial)
-			printf("nothing to commit%s\n", advice_status_hints
-				? " (create/copy files and use \"git add\" to track)" : "");
+			printf(_("nothing to commit%s\n"), advice_status_hints
+				? _(" (create/copy files and use \"git add\" to track)") : "");
 		else if (!s->show_untracked_files)
-			printf("nothing to commit%s\n", advice_status_hints
-				? " (use -u to show untracked files)" : "");
+			printf(_("nothing to commit%s\n"), advice_status_hints
+				? _(" (use -u to show untracked files)") : "");
 		else
-			printf("nothing to commit%s\n", advice_status_hints
-				? " (working directory clean)" : "");
+			printf(_("nothing to commit%s\n"), advice_status_hints
+				? _(" (working directory clean)") : "");
 	}
 }