* riece.el (riece-command-mode): Don't display

* riece.el (riece-command-mode): Don't display
riece-freeze-indicator on the modeline of the command buffer.
(riece-dialogue-mode): Make riece-freeze-indicator local to the
buffer whose major-mode is derived from riece-dialogue-mode.

* riece-display.el: Add autoload setting for derived-mode-class.
(riece-update-status-indicators): Check riece-freeze flag for each
buffer visible in the selected frame.

* riece-commands.el: Add autoload setting for derived-mode-class.
(riece-command-toggle-freeze): Don't switch to the channel buffer
if major-mode of the current buffer is derived from
riece-dialogue-mode.  Which allows to lock "*Others*" buffer.
(riece-command-toggle-own-freeze): Ditto.

* riece-globals.el (riece-freeze): Fix doc.
(riece-freeze-indicator): Add doc.
(riece-channel-indicator): Fix doc.
(riece-long-channel-indicator): Fix doc.
(riece-channel-list-indicator): Fix doc.
(riece-user-indicator): Fix doc.
(riece-away-indicator): Add doc.
(riece-operator-indicator): Add doc.