Remove redundant installation instructions

* lisp/net/newsticker.el:
* lisp/net/sieve-mode.el:
* lisp/play/bubbles.el:
* lisp/play/handwrite.el:
* lisp/progmodes/python.el:
* lisp/progmodes/ruby-mode.el:
* lisp/whitespace.el: Remove redundant installation instructions.
These packages are distributed with Emacs and/or GNU ELPA.
* lisp/calendar/timeclock.el:
* lisp/ehelp.el:
* lisp/emacs-lisp/checkdoc.el:
* lisp/filesets.el:
* lisp/mail/reporter.el:
* lisp/net/rfc2104.el:
* lisp/net/webjump.el:
* lisp/pixel-scroll.el: Remove redundant recommendation to call
require before using autoloaded functions.
* lisp/tar-mode.el: Remove reference to package uncompress, removed in
Emacs 23.

lisp/emacs-lisp/checkdoc.el

@@ -37,7 +37,6 @@
 ;;      documentation whenever you evaluate Lisp code with C-M-x
 ;;      or [menu-bar emacs-lisp eval-buffer].  Additional key-bindings
 ;;      are also provided under C-c ? KEY
-;;        (require 'checkdoc)
 ;;        (add-hook 'emacs-lisp-mode-hook 'checkdoc-minor-mode)
 ;;
 ;; Using `checkdoc':