added the vgmtools scource

diff --git a/src/util/vgmtools b/src/util/vgmtools
new file mode 160000 (submodule)
index 0000000..e145e64
--- /dev/null
+++ b/src/util/vgmtools
@@ -0,0 +1 @@
+Subproject commit e145e64fc31558f31a9d249f0d0f4ba585e6d338