Sets a device change notification callback.
BOOL BASS_WASAPI_SetNotify(
    WASAPINOTIFYPROC *proc,
    void *user
);
| proc | User defined notification function... NULL = disable notifications. | 
| user | User instance data to pass to the callback function. | 
| BASS_ERROR_WASAPI | WASAPI is not available. | 
If the BASSWASAPI DLL is loaded dynamically (eg. via LoadLibrary), this function should be called with NULL parameters prior to unloading the DLL.