Prefer "Bug#1234" in commit messages

* .dir-locals.el (log-edit-mode): Don't rewrite Bug#,
as this isn't useful for Git.
* CONTRIBUTE: Suggest "Bug#1234" instead of "Fixes: debbugs:1234".

.dir-locals.el

@@ -3,9 +3,7 @@
          (fill-column . 70)))
  (c-mode . ((c-file-style . "GNU")))
  (objc-mode . ((c-file-style . "GNU")))
- (log-edit-mode . ((log-edit-rewrite-fixes
-                    "[ \n](bug#\\([0-9]+\\))" . "debbugs:\\1")
-                   (log-edit-font-lock-gnu-style . t)
+ (log-edit-mode . ((log-edit-font-lock-gnu-style . t)
                    (log-edit-setup-add-author . t)))
  (change-log-mode . ((add-log-time-zone-rule . t)
 		     (fill-column . 74)

CONTRIBUTE

@@ -42,12 +42,11 @@ in its message.  Here is an example commit message (indented):
 	Deactivate shifted region
 
 	Do not silently extend a region that is not highlighted;
-	this can happen after a shift.
+	this can happen after a shift (Bug#19003).
 	* doc/emacs/mark.texi (Shift Selection): Document the change.
 	* lisp/window.el (handle-select-window):
 	* src/frame.c (Fhandle_switch_frame, Fselected_frame):
 	Deactivate the mark.
-	Fixes: bug#19003
 
 The general format is as follows.
 
@@ -113,11 +112,9 @@ The general format is as follows.
 
 	Copyright-paperwork-exempt: yes
 
-- If the commit fixes a bug, append a separate line
-
-	Fixes: bug#NNNN
-
-  where NNNN is the bug number.
+- The commit message should contain "Bug#NNNNN" if it is related to
+  bug number NNNNN in the debbugs database.  This string is often
+  parenthesized, as in "(Bug#19003)".
 
 - In ChangeLog entries, there is no standard or recommended way to
   identify revisions.