Audaspace: porting minor improvements from upstream

- NullDevice is now called None
- Automatic choice of best available device.
- Minor formatting, documentation and cmake fixes.

source/blender/windowmanager/intern/wm_playanim.c

@@ -1619,7 +1619,7 @@ void WM_main_playanim(int argc, const char **argv)
 
     AUD_initOnce();
 
-    if (!(audio_device = AUD_init("OpenAL", specs, 1024, "Blender"))) {
+    if (!(audio_device = AUD_init(NULL, specs, 1024, "Blender"))) {
       audio_device = AUD_init("Null", specs, 0, "Blender");
     }
   }

source/creator/creator_args.c

@@ -1330,7 +1330,7 @@ static const char arg_handle_audio_set_doc[] =
     "\n\t"
     "Force sound system to a specific device."
     "\n\t"
-    "'NULL' 'SDL' 'OPENAL' 'JACK'.";
+    "'None' 'SDL' 'OpenAL' 'JACK'.";
 static int arg_handle_audio_set(int argc, const char **argv, void *UNUSED(data))
 {
   if (argc < 1) {