Deprecating widgets in libgnomeui

[Jonathan Blandford <jrb redhat com>]

Given that we're now compiling GNOME with GTK+-2.3, I've gone through
libgnomeui and deprecated a number of widgets.  

        GnomeColorPicker
        GnomeEntry
        GnomeFileEntry
        GnomeFontPicker
        GnomePixmapEntry
        GnomePopupMenu

In addition, I deprecated gnome-window.h because it was pretty silly and
didn't agree with the HIG at all.  All of these widgets have an
equivalents in GTK+.

Thanks,
-Jonathan