Log Message:
faudio: updated to 21.04

21.04

New Features:
* Added support for SDL_GetAudioDeviceSpec, coming in a future SDL release
* FACT: Implemented accurate Fast/Slow/SinCos RPC curve types
* Added support for XMA2 audio, for Xbox 360 data

Fixes:
* Voice filters/effects should be processed even when SendCount is 0
* FACT:
  - Fix parsing/calculation of filter Q factors
  - Enforce STOPPING flag for fade-outs or RPC releases
  - Various fixes for parsing big-endian SoundBanks