* riece-log.el (riece-log-coding-system): New user option.

* riece-log.el (riece-log-coding-system): New user option.
(riece-log-display-message-function): Bind
coding-system-for-write; don't create temp buffer.

* riece-rdcc.el (riece-rdcc-filter): Use write-region instead of
append-to-file to suppress "Wrote file" messages.