Make git-check-format-ref a builtin.

Signed-off-by: Lukas Sandström <lukass@etek.chalmers.se>
Signed-off-by: Junio C Hamano <junkio@cox.net>

builtin-check-ref-format.c

@@ -0,0 +1,14 @@
+/*
+ * GIT - The information manager from hell
+ */
+
+#include "cache.h"
+#include "refs.h"
+#include "builtin.h"
+
+int cmd_check_ref_format(int argc, const char **argv, char **envp)
+{
+	if (argc != 2)
+		usage("git check-ref-format refname");
+	return !!check_ref_format(argv[1]);
+}