TODO: Allow substring/replace() to get/set bit values

Hi all,


I would like to work on "Allow substring/replace() to get/set bit values", since it looks like a simple task.

The item is not marked as "easy" on the TODO though. Before proceding to a discussion on how this functions should be
implemented(I got from the messages on the mailing list that bit substring/replace functions should do it) I would like
toknow if it's a complicated task. 


Leonardo