Log Message:
Update libopus to 1.1.1:

This Opus 1.1.1 release brings many optimizations to the encoder
and decoder, including:

*   x86 SSE, SSE2 and SSE4.1 intrinsics optimizations with run-time
    CPU detection contributed by Cisco Systems,
*   MIPS intrinsics optimizations contributed by Imagination
    Technologies,
*   ARM Neon optimizations contributed by Linaro and ARM,
*   many architecture-independent optimizations and memory footprint
    reductions that should improve performance on all platforms,
    and
*   several minor bug fixes.

The quality of the encoder should be mostly unchanged compared to
version 1.1.