Simon Hug
The two tests test/testaudioinfo.c and test/testaudiohotplug.c are missing error checking when they call SDL_GetAudioDeviceName. This function can return NULL which the tests pass straight to SDL_Log.
This fills in the core pieces and fully implements it for Mac OS X.
Most other platforms, at the moment, will report a disconnected device if
it fails to write audio, but don't notice if the system's device list changed
at all.
