(perform-replace): Add parameters START and END. Use

(perform-replace): Add parameters START and END.  Use
them instead of the check for a region in Transient Mark mode.
(query-replace-read-args): Return two more list elements for the
start and end of the region in Transient Mark mode.
(query-replace, query-replace-regexp, query-replace-regexp-eval)
(map-query-replace-regexp, replace-string, replace-regexp): Add
optional last arguments START and END and pass them to
perform-replace.