including version in template disclaimer

Author: cjac

templates/common/template_disclaimer

@@ -1,5 +1,8 @@
+#
+# Google Cloud Dataproc Initialization Actions v[% IA_VERSION %]
+#
 # This initialization action is generated from
-# initialization-actions/templates/[% template_path %]
+# initialization-actions/templates/[% template_path %].in
 #
-# Modifications made directly to the generated file will be lost when
-# the template is re-evaluated
+# Modifications made directly to generated files will be lost when the
+# templates are next evaluated.