C-c C-z conflicts between browse-url and message.el

[Andrew M. Scott]

The browse-url comments currently recommend the use of C-c C-z as a
prefix in a user's ~/.emacs [I use these]:

;; Bind the browse-url commands to keys with the `C-c C-z' prefix
;; (as used by html-helper-mode):
;;      (global-set-key "\C-c\C-z." 'browse-url-at-point)
;;      (global-set-key "\C-c\C-zb" 'browse-url-of-buffer)
;;      (global-set-key "\C-c\C-zr" 'browse-url-of-region)
;;      (global-set-key "\C-c\C-zu" 'browse-url)
;;      (global-set-key "\C-c\C-zv" 'browse-url-of-file)
;;      (add-hook 'dired-mode-hook
;;                (lambda ()
;;                   (local-set-key "\C-c\C-zf" 'browse-url-of-dired-file)))


However, this conflicts with the default message-mode-map
binding in message.el, where C-c C-z is not a prefix.

(define-key message-mode-map "\C-c\C-z" 'message-kill-to-signature)

I encountered this in GNUS when trying to
verify a link (via browse-url-at-point in the *mail* buffer)
before forwarding it.

In GNU Emacs 22.0.50.1 (x86_64-unknown-linux-gnu, X toolkit)
 of 2006-02-27 on chlr5836