add a tool to convert storages to new format

tools/storage_convert.py

@@ -0,0 +1,14 @@
+#!/usr/bin/env python
+
+from __future__ import with_statement
+
+import sys
+
+for name in sys.argv[1:]:
+    with open(name, 'r') as f:
+        lines = f.readlines()
+
+    with open(name, 'w') as f:
+        f.write('backends:\n')
+        for line in lines:
+            f.write('  %s' % line)