Allows any user to change the topic after the last | character so
non-opped users can change part of the topic. | characters in this topic are
replaced with a different character so that non-op users can't shift the end
of the user-modifiable topic.

Optionally, the script can also log all topic changes to an SQLite database
so previous topics can be displayed on a website using a CGI script written
in Tcl (See www directory).