* riece-unread.el (riece-unread-after-display-message-function):

Rename from riece-unread-display-message-function.
(riece-unread-after-switch-to-channel-function): Rename from
riece-unread-channel-switch-hook.
(riece-guess-channel-from-unread): New function.
(riece-unread-requires): Require 'riece-guess and 'riece-history.
(riece-unread-insinuate): Setup riece-guess-channel-try-functions.

* riece-options.el (riece-addons): Add riece-guess, riece-history,
and riece-url.

* riece-layout.el (riece-reconfigure-windows-predicate): Don't
check riece-last-channel.

* riece-display.el (riece-switch-to-channel): Rename
riece-channel-switch-hook to
riece-after-switch-to-channel-functions.
(riece-switch-to-nearest-channel): Ditto.

* riece-guess.el: New add-on.
* COMPILE (riece-modules): Add riece-guess.
* Makefile.am (EXTRA_DIST): Add riece-guess.el

* riece-history.el: New add-on.
* COMPILE (riece-modules): Add riece-history.
* Makefile.am (EXTRA_DIST): Add riece-history.el