* lisp/gnus-namazu.el (gnus-namazu-query-highlight): New option.

* lisp/gnus-namazu.el (gnus-namazu-query-highlight): New option.
(gnus-namazu-query-highlight-face): New face.
(gnus-namazu/check-cache-group): New function.
(gnus-namazu/cache-group-candidates): Ditto.
(gnus-namazu/search): Call `gnus-namazu/check-cache-group' to get
groups for cached articles.
(gnus-namazu/highlight-words): New function.
(gnus-namazu-search): Set the group parameter `highlight-words'
when `gnus-namazu-query-highlight' is equal to the other value
than nil.

* lisp/gnus-ja.texi (Namazu Groups): Updated.