(ibuffer-category-alist): Delete.

(ibuffer-category-alist): Delete.
(ibuffer-get-category): Delete.
(ibuffer-compile-make-eliding-form): Use `font-lock-face' instead
of categories.
(ibuffer-compile-format): Don't treat `name' category specially.
(ibuffer-column name): Use `font-lock-face'.
(filename-and-process): Ditto.
(ibuffer-buffer-name-category): Renamed to
`ibuffer-buffer-name-face'.  Don't use categories.
(ibuffer-update-title-and-summary): Use `font-lock-face'.
(ibuffer-insert-filter-group): Ditto.
(ibuffer-mode): Don't set up categories.