Miniaudio

- Fix compilation errors and warnings.

- Changed MAL_IMPLEMENTATION to MINI_AL_IMPLEMENTATION for consistency with other libraries. The old
way is still supported for now, but you should update as it may be removed in the future.
- API CHANGE: Replace device enumeration APIs. mal_enumerate_devices() has been replaced with
mal_context_get_devices(). An additional low-level device enumration API has been introduced called
mal_context_enumerate_devices() which uses a callback to report devices.
- API CHANGE: Rename mal_get_sample_size_in_bytes() to mal_get_bytes_per_sample() and add
mal_get_bytes_per_frame().
- API CHANGE: Replace mal_device_config.preferExclusiveMode with mal_device_config.shareMode.
- This new config can be set to mal_share_mode_shared (default) or mal_share_mode_exclusive.
- API CHANGE: Remove excludeNullDevice from mal_context_config.alsa.
- API CHANGE: Rename MAL_MAX_SAMPLE_SIZE_IN_BYTES to MAL_MAX_PCM_SAMPLE_SIZE_IN_BYTES.
- API CHANGE: Change the default channel mapping to the standard Microsoft mapping.
- API CHANGE: Remove backend-specific result codes.
- API CHANGE: Changes to the format conversion APIs (mal_pcm_f32_to_s16(), etc.)
- Add support for Core Audio (Apple).
- Add support for PulseAudio.
- This is the highest priority backend on Linux (higher priority than ALSA) since it is commonly
installed by default on many of the popular distros and offer's more seamless integration on
platforms where PulseAudio is used. In addition, if PulseAudio is installed and running (which
is extremely common), it's better to just use PulseAudio directly rather than going through the
"pulse" ALSA plugin (which is what the "default" ALSA device is likely set to).
- Add support for JACK.
- Remove dependency on asound.h for the ALSA backend. This means the ALSA development packages are no
longer required to build miniaudio.
- Remove dependency on dsound.h for the DirectSound backend. This fixes build issues with some
distributions of MinGW.
- Remove dependency on audioclient.h for the WASAPI backend. This fixes build issues with some
distributions of MinGW.
- Add support for dithering to format conversion.
- Add support for configuring the priority of the worker thread.
- Add a sine wave generator.
- Improve efficiency of sample rate conversion.
- Introduce the notion of standard channel maps. Use mal_get_standard_channel_map().
- Introduce the notion of default device configurations. A default config uses the same configuration
as the backend's internal device, and as such results in a pass-through data transmission pipeline.
- Add support for passing in NULL for the device config in mal_device_init(), which uses a default
config. This requires manually calling mal_device_set_send/recv_callback().
- Add support for decoding from raw PCM data (mal_decoder_init_raw(), etc.)
- Make mal_device_init_ex() more robust.
- Make some APIs more const-correct.
- Fix errors with SDL detection on Apple platforms.
- Fix errors with OpenAL detection.
- Fix some memory leaks.
- Fix a bug with opening decoders from memory.
- Early work on SSE2, AVX2 and NEON optimizations.
- Miscellaneous bug fixes.
- Documentation updates.

- API CHANGE: Change mal_src_read_frames() and mal_dsp_read_frames() to use 64-bit sample counts.
- Add decoder APIs for loading WAV, FLAC, Vorbis and MP3 files.
- Allow opening of devices without a context.
- In this case the context is created and managed internally by the device.
- Change the default channel mapping to the same as that used by FLAC.
- Fix build errors with macOS.

- API CHANGE: Expose and improve mutex APIs. If you were using the mutex APIs before this version you'll
need to update.
- API CHANGE: SRC and DSP callbacks now take a pointer to a mal_src and mal_dsp object respectively.
- API CHANGE: Improvements to event and thread APIs. These changes make these APIs more consistent.
- Add support for SDL and Emscripten.
- Simplify the build system further for when development packages for various backends are not installed.
With this change, when the compiler supports __has_include, backends without the relevant development
packages installed will be ignored. This fixes the build for old versions of MinGW.
- Fixes to the Android build.
- Add mal_convert_frames(). This is a high-level helper API for performing a one-time, bulk conversion of
audio data to a different format.
- Improvements to f32 -> u8/s16/s24/s32 conversion routines.
- Fix a bug where the wrong value is returned from mal_device_start() for the OpenSL backend.
- Fixes and improvements for Raspberry Pi.
- Warning fixes.

- Fix build errors with BSD/OSS.

- Fix some warnings when compiling with Visual C++.