In my very basic test that lists sftp://127.0.0.1/tmp/, this patched code makes 161 allocations compared to 194 in git master. A 17% reduction. Closes #5336
Adds support for SFTP (not SCP) using WolfSSH. Closes #4231
Follow-up to 5b2d703 which moved ssh source files to vssh. Closes https://github.com/curl/curl/pull/4609
5b2d703