Log Message:
Update to 0.21

Upstream changes:
0.21 -- Mon Jun 10 20:24:50 ADT 2024

    [Updates since 0.19]
    A patch from @ppisar to quiet unused variable warnings. Thanks!

    [Detailed Change Log]
    - 855254d Update Copright year and increment version
    - f54d079 Fix warning about unused variables
    - 1f84bf8 v0.20

0.20 -- Sun Jun 09 21:25:57 ADT 2024

    [Significant updates since 0.19]
    Nothing significant, fixing a couple of issues on older openssl

    [Detailed Change Log]
    - 7488425 Fix some signedness warnings
    - 5bc4f89 Updates for release
    - 38a2151 Variables used in all versions should not be #ifed
    - 96bea8b Update for some possible issues with older versions
    - d295be6 Fix tests failed on really old openssl versions
    - 24bb8b1 Update repo version
    - 0a52626 (tag: 0.19) v0.19