'dir' is not very descriptive (of course it's a direction!), it's better
to include 'default' in the name to indicate this is the default value
to use in absence of a specific one.
git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@74788 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775
