bug#2356: 23.0.90; customize-group of flymake signals error

[martin rudalics]

> After emacs-snapshot -Q, M-x customize-group flymake signals an error
> widget-apply: Wrong type argument: char-or-string-p, nil
>
> In GNU Emacs 23.0.90.1 (i486-pc-linux-gnu, GTK+ Version 2.12.11)
>  of 2009-02-17 on tiny.isode.net, modified by Debian
>  (emacs-snapshot package, version 1:20090207-1)
> Windowing system distributor `The X.Org Foundation', version 11.0.10402000
> configured using `configure  '--build' 'i486-linux-gnu' '--host' 
'i486-linux-gnu' '--prefix=/usr' '--sharedstatedir=/var/lib' 
'--libexecdir=/usr/lib' '--localstatedir=/var' '--infodir=/usr/share/info' 
'--mandir=/usr/share/man' '--with-pop=yes' 
'--enable-locallisppath=/etc/emacs-snapshot:/etc/emacs:/usr/local/share/emacs/23.0.90/site-lisp:/usr/local/share/emacs/site-lisp:/usr/share/emacs/23.0.90/site-lisp:/usr/share/emacs/site-lisp'
 '--with-x=yes' '--with-x-toolkit=gtk' 'build_alias=i486-linux-gnu' 
'host_alias=i486-linux-gnu' 'CFLAGS=-DDEBIAN -DSITELOAD_PURESIZE_EXTRA=5000 -g 
-O2' 'LDFLAGS=-g -Wl,--as-needed' 'CPPFLAGS=''

IIUC, there's simply no customization group called `flymake'.

So adding something like

(defgroup flymake nil
  "Flymake."
  :version "23.1"
  :group 'tools)

to flymake.el should fix this.

martin