SDL API renaming: SDL_audio.h

[slouken]

Here are proposed name changes for functions in SDL_audio.h, per discussion in #6569

SDL_AudioInit => SDL_InitAudio
SDL_AudioQuit => SDL_QuitAudio
SDL_AudioStreamAvailable => SDL_GetAudioStreamAvailable
SDL_AudioStreamClear => SDL_ClearAudioStream
SDL_AudioStreamFlush => SDL_FlushAudioStream
SDL_AudioStreamGet => SDL_GetAudioStreamData
SDL_AudioStreamPut => SDL_PutAudioStreamData
SDL_BuildAudioCVT
SDL_ClearQueuedAudio
SDL_CloseAudio
SDL_CloseAudioDevice
SDL_ConvertAudio
SDL_DequeueAudio
SDL_FreeAudioStream => SDL_DestroyAudioStream
SDL_FreeWAV
SDL_GetAudioDeviceName
SDL_GetAudioDeviceSpec
SDL_GetAudioDeviceStatus
SDL_GetAudioDriver
SDL_GetAudioStatus
SDL_GetCurrentAudioDriver
SDL_GetDefaultAudioInfo
SDL_GetNumAudioDevices
SDL_GetNumAudioDrivers
SDL_GetQueuedAudioSize
SDL_LoadWAV_RW
SDL_LockAudio
SDL_LockAudioDevice
SDL_MixAudio
SDL_MixAudioFormat
SDL_NewAudioStream => SDL_CreateAudioStream
SDL_OpenAudio
SDL_OpenAudioDevice
SDL_PauseAudio
SDL_PauseAudioDevice
SDL_QueueAudio
SDL_UnlockAudio
SDL_UnlockAudioDevice

@libsdl-org/a-team for discussion?

[icculus]

So reading through these makes me realize there are several changes I want to make that have nothing to do with naming (SDL_FreeWAV should be removed, it's just a wrapper over SDL_free(), etc), and I'll open separate issues for those.

Beyond that, audio changes look good to me.