Misc doc fixes.

Misc doc fixes.

* searching.texi (Replacing Match): Minor clarification.

* lisp/repeat.el (repeat): Doc fix.

* lisp/simple.el (shell-command-on-region): Doc fix.

* lisp/emacs-lisp/easy-mmode.el (define-minor-mode): Doc fix.

* cmds.c (Fforward_char, Fbackward_char): Doc fix.

* editfns.c (Fline_beginning_position): Doc fix.
(Fline_end_position): Doc fix.

* minibuf.c (Finternal_complete_buffer): Doc fix.

* search.c (Freplace_match): Doc fix.

Fixes: debbugs:12325 debbugs:12391 debbugs:12416 debbugs:12414 debbugs:10909 debbugs:12348