todo: Removed ErcShow-like task.

We don't support commands.  They should be handled by weechat.
Instead of ErcShow write yourself a `fancy-eval-print-last-sexp' and
bind it to, e.g., C-j.  But this is not really weechat specific.

Signed-off-by: Rüdiger Sonderfeld <ruediger@c-plusplus.de>