These files are generated by the test servers and must therefore be
found in the log directory to make them available to only those servers
once multiple test runners are executing in parallel. They must also not
be deleted with the log files, so they are stored in the pidfile
directory.

Ref: #10818
Closes #10875

This will allow it be set dynamically.

Ref: #10818

This makes the tests easier to copy and relocate to other test numbers
without having to update content.

Closes #6738

OpenSSH for Windows shows group and other/world permissions as *,
because those concepts do not exist on Windows. It also does not
show the current or parent directory, so we just ignore those.

Reviewed-by: Daniel Stenberg
Closes #5328

OpenSSH for Windows requires paths in the format of /C:/
instead of the pseudo-POSIX paths /cygdrive/c/ or just /c/

Reviewed-by: Daniel Stenberg
Closes #5298

All these tests failed on Windows because something like
sftp://%HOSTIP:%SSHPORT%PWD/
expanded to
sftp://127.0.0.1:1234c:/msys64/home/bla/curl
and then curl complained about the port number ending with a letter.

Use the original POSIX path instead of the Windows path created in
checksystem to fix this.

Closes https://github.com/curl/curl/pull/2920