[Stk] new release 4.4.3

[Gary Scavone]

- https://ccrma.stanford.edu/software/stk/

- Changed SINT24 to be lower 3 bytes of 32-bit word.
- Bug fixes to vectorized tick functions in Effects classes.
- Updated versions of RtAudio and RtMidi.
- Bug fixes in ADSR and Envelope classes.
- Updates to the internal argument checking and reporting scheme.
- Updates to Bowed class (thanks to Esteban Maestre!).
- Fixes for 24-bit support in FileRead and FileWrite.
- Added WAVE_FORMAT_EXTENSIBLE support in FileWrite.
- Added sample rate variable reading and writing for MAT-files in FileRead and FileWrite.

--gary