Openbox doesn't look for hung processes at this time.
+ _NET_FRAME_EXTENTS (1.3)
+ _NET_WM_STATE_DEMANDS_ATTENTION (1.3)
-- _NET_RESTACK_WINDOW (1.3)
- Openbox doesn't support this at this time.
++ _NET_RESTACK_WINDOW (1.3)
+ _NET_WM_SYNC_REQUEST (1.3)
+ _NET_WM_FULL_PLACEMENT (1.4)
+ _NET_WM_MOVERESIZE_CANCEL (1.4)