Miniaudio

- Fix compilation errors on the iOS build.

- Fix some bugs with device tracking on Core Audio.
- Updates to documentation.

- Add include guard for the implementation section.
- Mark ma_device_sink_info_callback() as static.
- Fix compilation errors with MA_NO_DECODING and MA_NO_ENCODING.
- Fix compilation errors with MA_NO_DEVICE_IO

- Amalgamation of dr_wav, dr_flac and dr_mp3. With this change, including the header section of these libraries before the implementation of miniaudio is no
longer required. Decoding of WAV, FLAC and MP3 should be supported seamlessly without any additional libraries. Decoders can be excluded from the build
with the following options:
- MA_NO_WAV
- MA_NO_FLAC
- MA_NO_MP3
If you get errors about multiple definitions you need to either enable the options above, move the implementation of dr_wav, dr_flac and/or dr_mp3 to before
the implementation of miniaudio, or update dr_wav, dr_flac and/or dr_mp3.
- Changes to the internal atomics library. This has been replaced with c89atomic.h which is embedded within this file.
- Fix a bug when a decoding backend reports configurations outside the limits of miniaudio's decoder abstraction.
- Fix the UWP build.
- Fix the Core Audio build.
- Fix the -std=c89 build on GCC.

- Remove dependency on ma_context from mutexes.
- Change ma_data_source_read_pcm_frames() to return a result code and output the frames read as an output parameter.
- Change ma_data_source_seek_pcm_frames() to return a result code and output the frames seeked as an output parameter.
- Change ma_audio_buffer_unmap() to return MA_AT_END when the end has been reached. This should be considered successful.
- Change playback.pDeviceID and capture.pDeviceID to constant pointers in ma_device_config.
- Add support for initializing decoders from a virtual file system object. This is achieved via the ma_vfs API and allows the application to customize file
IO for the loading and reading of raw audio data. Passing in NULL for the VFS will use defaults. New APIs:
- ma_decoder_init_vfs()
- ma_decoder_init_vfs_wav()
- ma_decoder_init_vfs_flac()
- ma_decoder_init_vfs_mp3()
- ma_decoder_init_vfs_vorbis()
- ma_decoder_init_vfs_w()
- ma_decoder_init_vfs_wav_w()
- ma_decoder_init_vfs_flac_w()
- ma_decoder_init_vfs_mp3_w()
- ma_decoder_init_vfs_vorbis_w()
- Add support for memory mapping to ma_data_source.
- ma_data_source_map()
- ma_data_source_unmap()
- Add ma_offset_pcm_frames_ptr() and ma_offset_pcm_frames_const_ptr() which can be used for offsetting a pointer by a specified number of PCM frames.
- Add initial implementation of ma_yield() which is useful for spin locks which will be used in some upcoming work.
- Add documentation for log levels.
- The ma_event API has been made public in preparation for some uncoming work.
- Fix a bug in ma_decoder_seek_to_pcm_frame() where the internal sample rate is not being taken into account for determining the seek location.
- Fix some bugs with the linear resampler when dynamically changing the sample rate.
- Fix compilation errors with MA_NO_DEVICE_IO.
- Fix some warnings with GCC and -std=c89.
- Fix some formatting warnings with GCC and -Wall and -Wpedantic.
- Fix some warnings with VC6.
- Minor optimization to ma_copy_pcm_frames(). This is now a no-op when the input and output buffers are the same.

- Fix a compilation error in the C++ build.
- Silence a warning.