Box Backup

Fix test failing on OpenBSD because tar -m behaves differently.

Fix more minor test breaks on Windows

Fix test to handle console encoding already in UTF-8.

Fix random timezone errors on restore. Work in UTC inside Box Backup, not local time.

Remove unused variable

Fix error logging when file open fails on Windows. We need to use the saved Windows error code from GetLastError?(), rather than calling it again, because another system call has run in the mean time and GetLastError?() will now return 0.

Write memory leak report files to current working directory saved at startup. Fixes tests broken by changing current directory, for example in bbackupquery, which meant that the report file was written in the wrong place and couldn't be found by the test, causing a failure.

Improve internal debug logging

Fix overlapped I/O in WinNamedPipeStream?. Broken by previous changes to introduce overlapped I/O for writes.

Whitespace and comment fixes. Improve correctness and reduce code duplication in bbackupctl.