gnu: lz4: Update to 1.7.5.

* gnu/packages/compression.scm (lz4): Update to 1.7.5.
[source]: Update source URL. Use patch 'lz4-fix-test-failures.patch'.
[home-page]: Update URL.
* gnu/packages/patches/lz4-fix-test-failures.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.

Merge branch 'core-updates'

Merge branch 'master' into core-updates

Most conflicts are from 6fd52309b8f52c9bb59fccffac53e029ce94b698.

gnu: Use HTTPS for almost all gnu.org HOME-PAGEs.

All HTTP gnu.org (and supported subdomain) HOME-PAGEs changed to HTTPS.

gnu: zstd: Update to 1.1.4.

* gnu/packages/compression.scm (zstd): Update to 1.1.4.

Revert "gnu: snappy: Update to 1.1.4."

Rocksdb fails to build with this version:
https://github.com/facebook/rocksdb/issues/1947

This reverts commit 9baab9aeeda394408290613c597bff1d96004dfb.

Merge remote-tracking branch 'origin/master' into core-updates

gnu: perl-io-compress: Update to 2.074.

* gnu/packages/compression.scm (perl-io-compress): Update to 2.074.
[propagated-inputs]: Update minimum versions to 2.074.

gnu: perl-compress-raw-bzip2: Update to 2.074.

* gnu/packages/compression.scm (perl-compress-raw-bzip2): Update to 2.074.

gnu: perl-compress-raw-zlib: Update to 2.074.

* gnu/packages/compression.scm (perl-compress-raw-zlib): Update to 2.074.

Merge remote-tracking branch 'origin/master' into core-updates

gnu: Add pzstd.

* gnu/packages/compression.scm (pzstd): New variable.

gnu: Add zstd.

* gnu/packages/compression.scm (zstd): New variable.

Merge remote-tracking branch 'origin/master' into core-updates

gnu: Add minizip.

* gnu/packages/compression.scm (minizip): New variable.

Merge branch 'master' into core-updates

gnu: snappy: Update to 1.1.4.

* gnu/packages/compression.scm (snappy): Update to 1.1.4.

gnu: Add unrar.

* gnu/packages/compression.scm (unrar): New variable.

Merge branch 'master' into python-tests

Merge branch 'master' into core-updates