* riece.el (riece-dialogue-mode-map): Bind "p" to

riece-command-enter-message-to-user.

* riece-misc.el (riece-current-nickname): Use
riece-current-server-name.
(riece-get-users-on-server): Ditto.

* riece-server.el (riece-current-server-name): New function.
(riece-send-string): Use it.

* riece-commands.el (riece-command-enter-message-to-user): New command.