-- added set_base, get_base and configuration ini key indexBase, which control whether indexing starts at 0 or 1 in set_chars and get_chars
-- added modify() and addmake() members to set of exported functions for use by other plugins, and corrected documentation for others. -- fixed an obscure bug in the set of exported functions which might have resulted in a ommory leak when unicode plugin interacted with other plugins. -- I added slice, find and revfind 0-based services a few version ago, but forgot to update all the documentation. Mea culpa.
