package version metadata for external/

This will be used for automated notification of external vulnerability
reports.

Change-Id: Idb96aec010679e818bbf75ba55eb4e164c4be62c
diff --git a/README.version b/README.version
new file mode 100644
index 0000000..ac295e6
--- /dev/null
+++ b/README.version
@@ -0,0 +1,4 @@
+URL: http://www.daemonology.net/bsdiff/bsdiff-4.3.tar.gz
+Version: 4.3
+BugComponent: 31870
+AllAdvisories: yes