Registers a new accelerator with the global accelerator map. This function should only be called once per accel_path with the canonical accel_key and accel_mods for this path. To change the accelerator during runtime programatically, use gtk_accel_map_change_entry().
Set accel_key and accel_mods to 0 to request a removal of the accelerator.
Note that accel_path string will be stored in a GQuark Therefore, if you pass a static string, you can save some memory by interning it first with g_intern_static_string().