Changes: https://chromium.googlesource.com/webm/libwebp/+/1.2.1/NEWS
* lossless performance and compression improvements + a new 'cruncher' mode (-m 6 -q 100) * ARM performance improvements with clang (15-20% w/ndk r15c) * webp-js: emscripten/webassembly based javascript decoder * miscellaneous bug & build fixes