rusty_h264 0.12.0

A ground-up, pure-Rust H.264 encoder and decoder. Decoder bit-exact vs Cisco openh264 (Baseline + B-slices + most of High profile); encoder bit-exact vs ffmpeg. forbid(unsafe) codec core; portable Rust SIMD (SSE2/AVX2/NEON, no assembler) on by default — `--no-default-features` for pure scalar. BSD-2.