Log Message:
Updated zstd to 1.1.3.

v1.1.3
cli : zstd can decompress .gz files (can be disabled with `make zstd-nogz` or \ 
`make HAVE_ZLIB=0`)
cli : new : experimental target `make zstdmt`, with multi-threading support
cli : new : improved dictionary builder "cover" (experimental), by \ 
Nick Terrell
cli : new : advanced commands for detailed parameters, by Przemyslaw Skibinski
cli : fix zstdless on Mac OS-X, by Andrew Janke
cli : fix #232 "compress non-files"
dictBuilder : improved dictionary generation quality, thanks to Nick Terrell
API : new : lib/compress/ZSTDMT_compress.h multithreading API (experimental)
API : new : ZSTD_create?Dict_byReference(), requested by Bartosz Taudul
API : new : ZDICT_finalizeDictionary()
API : fix : ZSTD_initCStream_usingCDict() properly writes dictID into frame \ 
header, by Gregory Szorc (#511)
API : fix : all symbols properly exposed in libzstd, by Nick Terrell
build : support for Solaris target, by Przemyslaw Skibinski
doc : clarified specification, by Andrew Purcell