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");
     }
   }