Isolate IETF models in OpenConfig to own bundle

Change-Id: I15fff358582dd7b361d015c2d30c981a703fd1be
diff --git a/models/common/src/main/yang/TODO b/models/common/src/main/yang/TODO
new file mode 100644
index 0000000..6ab16df
--- /dev/null
+++ b/models/common/src/main/yang/TODO
@@ -0,0 +1 @@
+move out standard compliant IETF yangs to IETF bundle