Add chatty_utils_sanitize_filename() and use it in chatty-mmsd
find_url() looks for ()[],
as end delimiters. Filenames could have them and rather than try to make a complicated parser, we can strip them from filename instead.
This is in chatty-utils so it can also be used for other protocols.
Supercedes !1070 (closed)
Edited by Chris Talbot