treeviewcolumn: Don't swallow motion/crossing events

If the column is not clickable, it may make some sense to stop
event propagation here for button events. However motion events
should be left alone.

Fixes treeview column resize pointer cursors, since that's
implemented up the bubbling phase in the treeview.

gtk/gtktreeviewcolumn.c

@@ -1056,16 +1056,14 @@ gtk_tree_view_column_button_event (GtkWidget *widget,
       switch (event_type)
 	{
 	case GDK_BUTTON_PRESS:
-	case GDK_MOTION_NOTIFY:
 	case GDK_BUTTON_RELEASE:
-	case GDK_ENTER_NOTIFY:
-	case GDK_LEAVE_NOTIFY:
-	  return TRUE;
+          return GDK_EVENT_STOP;
 	default:
-	  return FALSE;
+          return GDK_EVENT_PROPAGATE;
 	}
     }
-  return FALSE;
+
+  return GDK_EVENT_PROPAGATE;
 }