Don't require jabber-console in defcustom of jabber-debug-log-xml

That makes it impossible to run Emacs if jabber-debug-log-xml has been
customized, but jabber-console.el is not in the load path for some
reason.  Instead add an autoload cookie for jabber-process-console to
ensure that it gets loaded when needed.  Also remove duplicate
definition of jabber-buffer-connection.

jabber-console.el

@@ -52,12 +52,6 @@ what kind of chat buffer is being created.")
 (defvar jabber-console-ewoc nil
   "The ewoc showing the XML elements of this stream buffer.")
 
-;;;###autoload
-(defvar jabber-buffer-connection nil
-  "The connection used by this buffer.")
-;;;###autoload
-(make-variable-buffer-local 'jabber-buffer-connection)
-
 (defvar jabber-console-mode-map
   (let ((map (make-sparse-keymap)))
     (set-keymap-parent map jabber-common-keymap)
@@ -134,6 +128,7 @@ what kind of chat buffer is being created.")
       (jabber-tree-map (lambda (x) (if (numberp x) (format "%s" x) x)) xml-data)
     xml-data))
 
+;;;###autoload
 (defun jabber-process-console (jc direction xml-data)
   "Log XML-DATA i/o as XML in \"*-jabber-console-JID-*\" buffer"
   (let ((buffer (get-buffer-create (jabber-console-create-buffer jc))))

jabber.el

@@ -202,8 +202,7 @@ configure a Google Talk account like this:
   :type '(choice (const :tag "Do not dump XML i/o" nil)
                  (const :tag "Dump XML i/o in console" t)
                  (string :tag "Dump XML i/o in console and this file"))
-  :group 'jabber-debug
-  :require 'jabber-console)
+  :group 'jabber-debug)
 
 ;;;###autoload
 (defcustom jabber-debug-keep-process-buffers nil