Zstd

bug: Use `umask()` to Constrain Created File Permissions (2495, felixhandte)
bug: Make Simple Single-Pass Functions Ignore Advanced Parameters (2498, terrelln)
api: Add (De)Compression Tracing Functionality (2482, terrelln)
api: Support References to Multiple DDicts (2446, senhuang42)
api: Add Function to Generate Skippable Frame (2439, senhuang42)
perf: New Algorithms for the Long Distance Matcher (2483, mpu)
perf: Performance Improvements for Long Distance Matcher (2464, mpu)
perf: Don't Shrink Window Log when Streaming with a Dictionary (2451, terrelln)
cli: Fix `--output-dir-mirror`'s Rejection of `..`-Containing Paths (2512, felixhandte)
cli: Allow Input From Console When `-f`/`--force` is Passed (2466, felixhandte)
cli: Improve Help Message (2500, senhuang42)
tests: Remove Flaky Tests (2455, 2486, 2445, Cyan4973)
tests: Correctly Invoke md5 Utility on NetBSD (2492, niacat)
tests: Avoid Using `stat -c` on NetBSD (2513, felixhandte)
build: Zstd CLI Can Now be Linked to Dynamic `libzstd` (2457, 2454 Cyan4973)
build: Hide and Avoid Using Static-Only Symbols (2501, 2504, skitt)
build: CMake: Enable Only C for lib/ and programs/ Projects (2498, concatime)
build: CMake: Use `configure_file()` to Create the `.pc` File (2462, lazka)
build: Fix Fuzzer Compiler Detection & Update UBSAN Flags (2503, terrelln)
build: Add Guards for `_LARGEFILE_SOURCE` and `_LARGEFILE64_SOURCE` (2444, indygreg)
build: Improve `zlibwrapper` Makefile (2437, Cyan4973)
contrib: Add `recover_directory` Program (2473, terrelln)
doc: Change License Year to 2021 (2452 & 2465, terrelln & senhuang42)
doc: Fix Typos (2459, ThomasWaldmann)

hotfix: wrong alignment of an internal buffer

perf: stronger --long mode at high compression levels, by senhuang42
perf: stronger --patch-from at high compression levels, thanks to --long improvements
perf: faster dictionary compression at medium compression levels, by felixhandte
perf: small speed & memory usage improvements for ZSTD_compress2(), by terrelln
perf: improved fast compression speeds with Visual Studio, by animalize
cli : Set nb of threads with environment variable ZSTD_NBTHREADS, by senhuang42
cli : accept decompressing files with *.zstd suffix
cli : provide a condensed summary by default when processing multiple files
cli : fix : stdin input no longer confused as user prompt
cli : improve accuracy of several error messages
api : new sequence ingestion API, by senhuang42
api : shared thread pool: control total nb of threads used by multiple compression jobs, by marxin
api : new ZSTD_getDictID_fromCDict(), by LuAPi
api : zlibWrapper only uses public API, and is compatible with dynamic library, by terrelln
api : fix : multithreaded compression has predictable output even in special cases (see 2327) (issue not accessible from cli)
api : fix : dictionary compression correctly respects dictionary compression level (see 2303) (issue not accessible from cli)
build: fix cmake script when using path with spaces, by terrelln
build: improved compile-time detection of aarch64/neon platforms, by bsdimp
build: Fix building on AIX 5.1, by likema
build: compile paramgrill with cmake on Windows, requested by mirh
doc : clarify repcode updates in format specification, by felixhandte

fix : Always return dstSize_tooSmall when that is the case
fix : Fix ZSTD_initCStream_advanced() with static allocation and no dictionary
perf: Improve small block decompression speed by 20%+, by terrelln
perf: Reduce compression stack usage by 1 KB, by terrelln
perf: Improve decompression speed by improving ZSTD_wildcopy, by helloguo (2252, 2256)
perf: Improve histogram construction, by cyan4973 (2253)
cli : Add --output-dir-mirror option, by xxie24 (2219)
cli : Warn when (de)compressing multiple files into a single output, by senhuang42 (2279)
cli : Improved progress bar and status summary when (de)compressing multiple files, by senhuang42 (2283)
cli : Call stat less often, by felixhandte (2262)
cli : Allow --patch-from XXX and --filelist XXX in addition to --patch-from=XXX and --filelist=XXX, by cyan4973 (2250)
cli : Allow --patch-from to compress stdin with --stream-size, by bimbashrestha (2206)
api : Do not install zbuff.h, since it has long been deprecated, by cyan4973 (2166).
api : Fix ZSTD_CCtx_setParameter() with ZSTD_c_compressionLevel to make 0 mean default level, by i-do-cpp (2291)
api : Rename ZSTDMT_NBTHREADS_MAX to ZSTDMT_NBWORKERS_MAX, by marxin (2228).
build: Install pkg-config file with CMake and MinGW, by tonytheodore (2183)
build: Install DLL with CMake on Windows, by BioDataAnalysis (2221)
build: Fix DLL install location with CMake, by xantares and bimbashrestha (2186)
build: Add ZSTD_NO_UNUSED_FUNCTIONS macro to hide unused functions
build: Add ZSTD_NO_INTRINSICS macro to avoid explicit intrinsics
build: Add STATIC_BMI2 macro for compile time detection of BMI2 on MSVC, by Niadb (2258)
build: Fix -Wcomma warnings, by cwoffenden
build: Remove distutils requirement for meson build, by neheb (2197)
build: Fix cli compilation with uclibc
build: Fix cli compilation without st_mtime, by ffontaine (2246)
build: Fix shadowing warnings in library
build: Fix single file library compilation with Enscripten, by yoshihitoh (2227)
misc: Improve single file library and include dictBuilder, by cwoffenden
misc: Allow compression dictionaries with missing symbols
misc: Add freestanding translation script in contrib/freestanding_lib
misc: Collect all of zstd's libc dependencies into zstd_deps.h
doc : Add ZSTD_versionString() to manual, by animalize
doc : Fix documentation for ZSTD_CCtxParams_setParameter(), by felixhandte (2270)

fix : Compression ratio regression on huge files (> 3 GB) using high levels (--ultra) and multithreading, by terrelln
perf: Improved decompression speed: x64 : +10% (clang) / +5% (gcc); ARM : from +15% to +50%, depending on SoC, by terrelln
perf: Automatically downsizes ZSTD_DCtx when too large for too long (2069, by bimbashreshta)
perf: Improved fast compression speed on aarch64 (2040, ~+3%, by caoyzh)
perf: Small level 1 compression speed gains (depending on compiler)
cli : New --patch-from command, create and apply patches from files, by bimbashreshta
cli : New --filelist= : Provide a list of files to operate upon from a file
cli : -b -d command can now benchmark decompression on multiple files
cli : New --no-content-size command
cli : New --show-default-cparams information command
api : ZDICT_finalizeDictionary() is promoted to stable (2111)
api : new experimental parameter ZSTD_d_stableOutBuffer (2094)
build: Generate a single-file libzstd library (2065, by cwoffenden)
build: Relative includes no longer require -I compiler flags for zstd lib subdirs (2103, by felixhandte)
build: zstd now compiles cleanly under -pedantic (2099)
build: zstd now compiles with make-4.3
build: Support mingw cross-compilation from Linux, by Ericson2314
build: Meson multi-thread build fix on windows
build: Some misc icc fixes backed by new ci test on travis
misc: bitflip analyzer tool, by felixhandte
misc: Extend largeNbDicts benchmark to compression
misc: Edit-distance match finder in contrib/
doc : Improved beginner CONTRIBUTING.md docs
doc : New issue templates for zstd

perf: Improved decompression speed, by > 10%, by terrelln
perf: Better compression speed when re-using a context, by felixhandte
perf: Fix compression ratio when compressing large files with small dictionary, by senhuang42
perf: zstd reference encoder can generate RLE blocks, by bimbashrestha
perf: minor generic speed optimization, by davidbolvansky
api: new ability to extract sequences from the parser for analysis, by bimbashrestha
api: fixed decoding of magic-less frames, by terrelln
api: fixed ZSTD_initCStream_advanced() performance with fast modes, reported by QrczakMK
cli: Named pipes support, by bimbashrestha
cli: short tar's extension support, by stokito
cli: command --output-dir-flat= , generates target files into requested directory, by senhuang42
cli: commands --stream-size= and --size-hint=, by nmagerko
cli: command --exclude-compressed, by shashank0791
cli: faster `-t` test mode
cli: improved some error messages, by vangyzen
cli: fix command `-D dictionary` on Windows, reported by artyompetrov
cli: fix rare deadlock condition within dictionary builder, by terrelln
build: single-file decoder with emscripten compilation script, by cwoffenden
build: fixed zlibWrapper compilation on Visual Studio, reported by bluenlive
build: fixed deprecation warning for certain gcc version, reported by jasonma163
build: fix compilation on old gcc versions, by cemeyer
build: improved installation directories for cmake script, by Dmitri Shubin
pack: modified pkgconfig, for better integration into openwrt, requested by neheb
misc: Improved documentation : ZSTD_CLEVEL, DYNAMIC_BMI2, ZSTD_CDict, function deprecation, zstd format
misc: fixed educational decoder : accept larger literals section, and removed UNALIGNED() macro