Update TODO, clean up bulkdata error message

TODO

@@ -1 +1,5 @@
-- Change BulkData filenames to a 2-layer structure (0000/0000)
+-- Clean up error responses.  Specifically I'd like to be able to add
+   json-formatted data to OverflowError and DB parsing errors.  It
+   seems like subclassing cherrypy.HTTPError and overriding
+   set_response is the best thing to do -- it would let me get rid
+   of the _be_ie_unfriendly and other hacks in the server.

nilmdb/bulkdata.py

@@ -71,7 +71,7 @@ class BulkData(object):
         [ group, node ] = path.rsplit("/", 1)
         if group == '':
             raise ValueError("invalid path; path must contain at least one "
-                             "folder (/foo/bar)")
+                             "folder")
 
         # Get layout, and build format string for struct module
         try: