get-wm-hints, set-wm-normal-hints!, get-wm-normal-hints,
create-gcontext, change-gcontext, get-visual-info,
change-window-attributes, get-window-attributes, configure-window,
create-window to use an enumerated type instead of symbols.
- renamed functions in xlib-client (e.g. wm-hints to get-wm-hints).