It is not needed in the relative case and causes issues when taking
sessions between platforms.
On windows, the default path would be "\export". When that is used
on linux the resulting fullpath would end up as
/your/session/path/\export
which is then not found on the file system.
This change is consistent with how relative paths are normally written and
does cure the default path when moved across platforms.
It does not solve the larger issue of mixed directory separators.
A relative path of "export\myMixV1" will still fail when moving between
platforms.
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