[opus] Opus 1.1 released

After more than two years of development, we have released Opus 1.1. This includes: * new analysis code and tuning that significantly improves encoding quality, especially for variable-bitrate (VBR), * automatic detection of speech or music to decide which encoding mode to use, * surround with good quality at 128 kbps for 5.1 and usable down to 48 kbps, and * speed improvements on all architectures, especially ARM, where decoding uses around 40% less CPU and encoding uses around 30% less CPU. These improvements are explained in more details in Monty's demo (updated from the 1.1 beta demo) at: http://people.xiph.org/~xiphmont/demo/opus/demo3.shtml Of course, this new version is still fully compliant with the Opus specification (RFC 6716). Download it from the website at http://opus-codec.org/ Cheers, Jean-Marc