Merge branch 'nd/daemonize-gc'

Allow running "gc --auto" in the background.

* nd/daemonize-gc:
  gc: config option for running --auto in background
  daemon: move daemonize() to libgit.a

setup.c

@@ -841,3 +841,27 @@ void sanitize_stdfds(void)
 	if (fd > 2)
 		close(fd);
 }
+
+int daemonize(void)
+{
+#ifdef NO_POSIX_GOODIES
+	errno = ENOSYS;
+	return -1;
+#else
+	switch (fork()) {
+		case 0:
+			break;
+		case -1:
+			die_errno("fork failed");
+		default:
+			exit(0);
+	}
+	if (setsid() == -1)
+		die_errno("setsid failed");
+	close(0);
+	close(1);
+	close(2);
+	sanitize_stdfds();
+	return 0;
+#endif
+}