patch for gtk-970916: better ICCCM window manager hints
          patch version 970923

          Gregor Hoffleit <[email protected]>

Enhances ICCCM support in GTK apps:
- WM_HINTS.window_group: gdk_init creates an global, unmapped
 leader window (gdk_leader_window) that holds the default properties
 (here WM_CLASS) of all other windows.
- new cmd line options "-name NAME" and "-class CLASS" to set
 WM_CLASS property (resname and classname).
- the WM_ICON_NAME property for a window is set to the same
 value as WM_NAME
- the WM_COMMAND property of the leader window is set to support
 session management

Effect:
- window managers that adhere to the ICCCM window group concept
 (e.g. wmaker) learn that all windows belong to one app.
- window managers that exploit WM_ICON_NAME (wmaker, mwm) can display
 the window's name in the icon.
- session managers can exploit WM_COMMAND to restart an app (e.g.
 `docking' of GTK apps with wmaker is now possible).