add status.relativePaths config variable

The output of git-status was recently changed to output relative
paths. Setting this variable to false restores the old behavior for
any old-timers that prefer it.

Signed-off-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

t/t7502-status.sh

@@ -88,4 +88,35 @@ test_expect_success 'status with relative paths' '
 
 '
 
+cat > expect << \EOF
+# On branch master
+# Changes to be committed:
+#   (use "git reset HEAD <file>..." to unstage)
+#
+#	new file:   dir2/added
+#
+# Changed but not updated:
+#   (use "git add <file>..." to update what will be committed)
+#
+#	modified:   dir1/modified
+#
+# Untracked files:
+#   (use "git add <file>..." to include in what will be committed)
+#
+#	dir1/untracked
+#	dir2/modified
+#	dir2/untracked
+#	expect
+#	output
+#	untracked
+EOF
+
+test_expect_success 'status without relative paths' '
+
+	git config status.relativePaths false
+	(cd dir1 && git status) > output &&
+	git diff expect output
+
+'
+
 test_done