* riece-globals.el (riece-strict-channel-regexp): Renamed from

riece-channel-regexp.
(riece-strict-user-regexp): Renamed from riece-user-regexp.
(riece-laxed-channel-regexp): New constant.
(riece-laxed-user-regexp): New constant.
(riece-channel-regexp): Define as variable (its default value is
set to riece-laxed-channel-regexp).
(riece-user-regexp): Define as variable (its default value is set
to riece-laxed-user-regexp).