Make speedbar sniff the PWD for mode specification lines

[Steven T. Hatton]

Symptoms:

This is a wishlist item.  I hope this is the place to send it.  One
development kit I am currently working with uses extensionless
headers, but does provide "/* -*-c++-*- OpenSceneGraph ..." on the
first line of all "header" files. (I would not have done that.) The
lack of extensions on the file names makes using many tools, including
Emacs speedbar, fairly difficult when trying to browse the include/
directory.  

I believe it is doable to make Emacs speedbar snif the first couple
lines of all the files in the current directory.  At what cost, I
don't know.  It would be a nice featur to have, but not if it
compromised other things.

In GNU Emacs 22.0.50.6 (i686-pc-linux-gnu, X toolkit, Xaw3d scroll bars)
 of 2005-05-18 on ljosalfr
Distributor `The X.Org Foundation', version 11.0.60802000
configured using `configure '--prefix=/home/hattons/opt/org/gnu/emacs-cvs''

Important settings:
  value of $LC_ALL: nil
  value of $LC_COLLATE: POSIX
  value of $LC_CTYPE: nil
  value of $LC_MESSAGES: nil
  value of $LC_MONETARY: nil
  value of $LC_NUMERIC: nil
  value of $LC_TIME: nil
  value of $LANG: en_US.UTF-8
  locale-coding-system: utf-8
  default-enable-multibyte-characters: t

Major mode: Dired by name

Minor modes in effect:
  delete-selection-mode: t
  pc-selection-mode: t
  show-paren-mode: t
  tool-bar-mode: t
  mouse-wheel-mode: t
  tooltip-mode: t
  auto-compression-mode: t
  menu-bar-mode: t
  global-font-lock-mode: t
  font-lock-mode: t
  blink-cursor-mode: t
  unify-8859-on-encoding-mode: t
  utf-translate-cjk-mode: t
  column-number-mode: t
  line-number-mode: t
  transient-mark-mode: t
  next-error-follow-minor-mode:  Fol

Recent input:
<left> <left> <left> <left> <left> <left> <S-end> <delete> 
f a i l C-x C-s C-x k <return> C-x C-f <up> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> e x <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
<backspace> <backspace> <backspace> <backspace> <backspace> 
$ O S G / <return> <help-echo> <down-mouse-2> <mouse-2> 
<help-echo> <help-echo> <help-echo> <down-mouse-2> 
<mouse-2> <help-echo> <help-echo> <help-echo> <down-mouse-2> 
<mouse-2> <help-echo> <help-echo> <help-echo> <down-mouse-2> 
<mouse-2> <help-echo> <help-echo> <down-mouse-3> <mouse-3> 
<help-echo> M-x r e p o r t <tab> <return>

Recent messages:
Wrote /download/org/openscenegraph/build-osg
line-move-1: Beginning of buffer [2 times]
Loading skeleton...done
Mark set [3 times]
Auto-saving...done
Mark set
Wrote /download/org/openscenegraph/build-osg
Loading dired...done
Loading ede-dired...done
Loading emacsbug...done