(hi-lock-archaic-interface-message-used)

(hi-lock-archaic-interface-message-used)
(hi-lock-archaic-interface-deduce, hi-lock-mode): Doc fix.
(hi-lock-mode): Display "Hi" in the mode line only when
hi-lock-interactive-patterns or hi-lock-file-patterns is non-nil.
(hi-lock-write-interactive-patterns):
Use hi-lock-file-patterns-prefix instead of hard-coded "Hi-lock".
(hi-lock-set-pattern, hi-lock-set-file-patterns)
(hi-lock-font-lock-hook): Set 3rd arg `how' of
font-lock-add-keywords to t.