Zstandard v1.5.7

Rename/Restructure Windows Release Artifact

https://github.com/facebook/zstd/releases/tag/v1.5.0 describes the structure
we want to adhere to. This commit tries to accomplish that automatically, so
we can avoid manual fixups on future releases.

Merge pull request facebook#3487 from facebook/dev

release v1.5.4

Zstandard v1.5.2 Release

Zstandard v1.5.1 Release

Note that a different commit was very briefly tagged as `v1.5.1`, before we
realized it was incomplete. That commit, f4a541b, and this commit, 791626d
are functionally equivalent. In the unlikely event that you caught this tag
pointing to that commit, do not be alarmed, and sorry for the churn.

Zstd 1.5.0 Release

Zstd 1.5.0 Release

Zstandard v1.4.9 Release

Merge pull request facebook#808 from facebook/dev

Zstandard v1.3.1

Merge pull request facebook#750 from facebook/dev

fixed wrong assert() condition

Merge pull request facebook#686 from facebook/dev

v1.2.0