modified xfce4 xfwm4 xfce-utils and libxfcegui4

[Olivier Fourdan]

Hi all,

I've changed configure.in/ac and spec files for the following packages :

- xfce4 
- xfwm4 
- xfce-utils
- libxfcegui4

The goal is to make sure required libs for build/rpm are listed, with
versions and keep the minimum version required at only one place
(configure.in/ac)

Other changes include proper use of AC_DEFINE/AC_DEFINE_UNQUOTED.

I've also changed xfbd4 to make use of the preview fileselector provided
by libxfcegui4

That makes a pretty big update...

Cheers,
-- 
Olivier               <fourdan at xfce.org>            http://www.xfce.org
-----------------------------------------------------------------------
XFce is a lightweight  desktop  environment  for  various *NIX systems. 
Designed for productivity,  it loads  and  executes  applications fast,
while conserving  system resources. XFce is all free software, released
under GNU General Public License.    Available from http://www.xfce.org